Raman

Dielectric optical invisibility cloaks
Paper 7756-7 of Conference 7756
Date: Monday, 02 August 2010

Author(s): John Blair, Georgia Institute of Technology (United States); Venkata A. Tamma, Won Park, Univ. of Colorado at Boulder (United States); Chris J. Summers, Georgia Institute of Technology (United States)

Transformation optical techniques can be applied to photonic crystal structures to create new optical invisibility cloaking devices. A recent design known as the 'carpet' cloak, compresses a curved reflective surface into a flat reflective surface, effectively shielding objects behind the curved area with respect to the incoming radiation source. This structure consists only of high index dielectrics, and operates in the 1400-1600nm wavelength range. A discussion of the design method, simulation analysis, device fabrication, and near field optical microscopy (NSOM) characterization results will be presented. Improvements to device performance through the infiltration of optical materials are currently under investigation.
Near field imaging of a plasmon photonic crystal patterned on the facet of a quantum cascade laser
Paper 7757-129 of Conference 7757
Date: Monday, 02 August 2010

Author(s): Dibyendu Dey, Ryan Gelfand, John Kohoutek, Alireza Bonakdar, Hooman Mohseni, Northwestern Univ. (United States)

We present a novel device, which combines a plasmon-polariton crystal (PPC) structure with edge emitting mid infrared Quantum cascade laser (QCL). The structure has been fabricated by coating the facet of QCL and further patterned using focused ion beam milling. Scanning optical microscopic (NSOM) technique has been used to image the effect of surface plasmon polariton on the optical mode of the laser. By studying the near field we can probe the spectral properties of our devices with a very controlled spatial resolution. Unlike photonic crystals and micro-ring resonators, this structure can produce a very large Purcell constant without sacrificing the optical bandwidth.
An apertureless near-field scanning optical microscope for imaging surface plasmons in the mid-wave infrared
Paper 7787-27 of Conference 7787
Date: Thursday, 05 August 2010

Author(s): John Kohoutek, Ryan Gelfand, Dibyendu Dey, Hooman Mohseni, Northwestern Univ. (United States)

We present an experimental technique for imaging surface plasmons in the mid-wave infrared region. The near field scanning optical microscope (NSOM) involves reflecting light from an edge emitting quantum-cascade-laser off of a metal coated atomic force microscope tip and then going back through the laser. We use a lock-in amplifier to lock to the harmonics of the AFM tip vibration frequency. This setup has topographic imaging in parallel with the infrared near-field such that the active source can easily be found. Detailed will be our experimental setup and results, with applications in biosensing, chemical sensing, plasmonic characterization, and laser diagnostics.

Assessment of ESD robustness in high power light-emitting diodes
Paper 7784-43 of Conference 7784
Date: Wednesday, 04 August 2010

Author(s): Shih-Chun Yang, Pang Lin, National Chiao Tung Univ. (Taiwan); Han-Kuei Fu, Chien-Ping Wang, Tzung-Te Chen, An-Tse Lee, Sheng-Bang Huang, Industrial Technology Research Institute (Taiwan)

The capability of high-power nitride-based light-emitting diodes (HPLED) to withstand electrostatic discharge (ESD) is very important key index due to the horizontal structure of the insulating property of the sapphire substrate. During the series ESD stress, atomic force microcopy (AFM) and conductive AFM (C-AFM) were applied to explore the correlation between surface morphology and electrical properties of LED chips, and transmission electron microscopy (TEM) was used to investigate the failure modes and compare to the distribution of the surface current observed by C-AFM. In the experiments, the correlation between the AFM topography image and the C-AFM current image confirms that surface morphology is responsible for the ESD endurance.
Surface characterization of polished glass substrate and carbon film using AFM and power spectral density function
Paper 7801-8 of Conference 7801
Date: Sunday, 01 August 2010

Author(s): Jingtao Zhu, Zhanshan Wang, Qiushi Huang, Tongji Univ. (China)

Surface roughness of the substrate before and after Carbon thin film deposition, were characterized by Atomic force microscopy (AFM) and its power spectral density function (PSD). Firstly, surface roughness of polished glass substrate was measured by AFM. Then, 30nm thickness Carbon film was deposited on the substrate using magnetron sputtering. AFM localization method was used to measure surface roughness almost at the same place. The results show that, the surface roughness increases after Carbon film deposition. In our experiment, Carbon thin film can not be used as smoothing layer for our polished glass substrate. Keywords: AFM; power spectral density function; polished glass substrate; Carbon film
Optical trapping meets atomic force microscopy: A precision force microscope for biophysics
Paper 7762-14 of Conference 7762
Date: Sunday, 01 August 2010

Author(s): Gavin M. King, Univ. of Missouri-Columbia (United States)

Single-molecule force spectroscopy studies have produced rich insights into the unfolding of individual proteins and nucleic acid structures. In a typical force spectroscopy experiment, an atomic force microscope (AFM) tip is coupled to a surface-adsorbed protein by pressing the tip into it. Force-extension curves are then generated by retracting the tip at a constant velocity using a piezoelectric (PZT) stage. Force is measured by cantilever deflection. Extension, or more precisely tip-sample separation, is deduced from the PZT stage position used to control the vertical tip position. Thus, this deduced extension is sensitive to the vertical mechanical drift of the AFM assembly (~10 nm/min). We have adapted techniques originally developed for precision optical trapping, and constructed an ultrastable AFM (King et al, Nano Letters 9, 1451, [2009]) in which the tip and the sample positions are independently measured by, and stabilized with respect to, a pair of laser foci in three dimensions. These lasers establish a local reference frame that is insensitive to long-term mechanical drift of the AFM assembly. This new measurement of position is complementary to the cantilever deflection sensing, which measures force. With this apparatus, we can routinely mechanically unfold proteins at slow pulling velocities (2 nm/s), which allows averaging to increase precision. We can also stop pulling altogether and hold the molecule at constant force while independently measuring tip-sample separation (σ ~ 0.2 nm). Alternatively, we can stabilize tip-sample separation and measure force (σ ~ 5 pN) over 100s of seconds. Using these techniques, we are studying the unfolding and re-folding of bacteriorhodopsin (BR), a model transmembrane protein.
Assessment of the mechanical integrity of silicon and diamond-like-carbon coated silicon atomic force microscope probes
Paper 7767-8 of Conference 7767
Date: Monday, 02 August 2010

Author(s): Kevin T. Turner, Jingjing Liu, David S. Grierson, Kumar Sridharan, Univ. of Wisconsin-Madison (United States); Robert W. Carpick, Univ. of Pennsylvania (United States)

The wear of atomic force microscope (AFM) probes is a critical issue in the performance of probe-based metrology and nanomanufacturing processes. In this work, diamond-like-carbon (DLC) was coated on Si AFM tips using a plasma ion implantation and deposition process. The wear performance of these DLC coated tips was compared to that of silicon tips through wear tests over scanning distances up to ~0.5 meters. The wear tests consist of a combination of contact-mode AFM scanning, transmission electron microscopy, and pull-off force measurements. The results show that adhesive forces and tip wear can be dramatically reduced using DLC coated probes.
Bidirectional reflectance distribution of a 2D thin-film photonic crystal patterned using an atomic-force microscope
Paper 7792-17 of Conference 7792
Date: Monday, 02 August 2010

Author(s): Nicholas C. Herr, Michael A. Marciniak, Alex G. Li, Larry W. Burggraf, Air Force Institute of Technology (United States)

Bidirectional reflectance distribution has been measured from an atomic-force-microscope (AFM)-patterned surface for the first time. The AFM was used to generate a 325-μm by 200-μm array of 400-nm surface features in a polystyrene film deposited on silicon. An SMS Complete Angle Scatter Instrument (CASI) was used to measure in-plane bidirectional reflectance at 633- and 544-nm wavelengths, and at both s and p incident polarizations. Negative-first-order diffraction peaks were observed and were consistent with feature spacing. An anomalous scatter peak, believed to be associated with guided-mode resonance of the structure, was also observed.
Nano pattern formation of phase change material by femto-second laser-induced forward transfer
Paper 7764-30 of Conference 7764
Date: Wednesday, 04 August 2010

Author(s): Bo Han Chen, Ming Lung Tzeng, National Taiwan Univ. (Taiwan); Cheng Hung Chu, National Taiwan Univ. (Taiwan) and National Taiwan Ocean Univ. (Taiwan); Chia Min Chang, Chung Hao Lu, Shih Chiang Yen, Chun Da Shiue, National Taiwan Univ. (Taiwan); Hai-Pang Chiang, National Taiwan Ocean Univ. (Taiwan); Din Ping Tsai, National Taiwan Univ. (Taiwan) and Academia Sinica (Taiwan) and National Applied Research Lab. (Taiwan)

We present a laser-induced forward transfer technique to fabricate the pattern with phase change material Ge2Sb2Te5 (GST). The as-deposited GST alloy films on a transparent substrate are transferred to the receiver substrate after a femto-second laser pulse irradiation (wavelength is 800 nm, and pulse duration is 150 fs). The dots patterns are fabricated with different volume and height-width ratio by changing the laser fluence and the air gap distance between donor and receiver. The topography of receiver substrate is studied by atomic force microscopy (AFM) and the transfer properties are analyzed. According to the AFM measured information, we found that the dot diameter is function of GST donor film thickness and laser fluence. The dot size is around 14 nm (thickness) x 500 nm (diameter). Fabrication of patterns composed of dots deposited on the receiver substrate were measured. Under appropriate annealing process, the shape and phase state transition of dots can be controlled.
Course: Nanoscale Dimensional Metrology and Physical Characterization
Date: Wednesday, 04 August 2010

Instructor(s): Vladimir A. Ukraintsev, Nanometrology International, Inc. (United States)

This course provides attendees with a working knowledge of in-line critical dimension and reference metrology as well as with the basics of some techniques of semiconductor physical characterization. It is based on metrology and physical characterization practices currently employed in nanoscale semiconductor research, development and manufacturing. The course starts with definitions of commonly used metrology terms, reviews current challenges and explains the importance of metrology and characterization in achieving R&D and manufacturing goals. Basic critical dimensional metrology (ECD, SEM, SIM, OCD, 3DAFM) and some nanoscale physical characterization techniques (c-AFM, SCM, SSRM, KPSPM, SPVSPM, TERS) are reviewed. Their physical principles, merits and limitations are discussed. The material leads to the conclusion that only a combination of metrology and characterization techniques can solve the complex problems which semiconductor and nanotechnology research, development and manufacturing are facing today. The final topic of the course is about future hybrid instrumentation and methodologies which are coming to nanoscale dimensional metrology and physical characterization.
Probing nanostructures and optoelectronic properties of bulk heterojunction solar cells processed with additives by photoconductive atomic force microscopy
Paper 7777-4 of Conference 7777
Date: Tuesday, 03 August 2010

Author(s): Thuc-Quyen T. Nguyen, Corey Hoven, Xuan-Dung Dang, Bright Walker, Chunki Kim, Guillermo C. Bazan, Univ. of California, Santa Barbara (United States)

Organic solar cells have obtained much attention in both academia and industry because they have the potential to produce low-cost plastic devices for alternative energy sources. In these devices, the performance depends strongly on the nanoscale film morphology and optoelectronic properties; therefore, it is important to control the nanoscale morphology and to probe these properties and correlate to the bulk measurements. Additives can be used to control the nanoscale morphology and the phase separation in bulk heterojunction solar cells. We combine dark and photoconductive atomic force microscopy (pc-AFM) to study nanoscale morphology and optoelectronic properties of bulk heterojunction solar cells based on low band gap conjugated polymers and [6,6] phenyl-C71-butyric acid methyl ester (PC71BM) system that was recently reported to have a power conversion efficiency over 5%. By controlling the applied voltage in photoconductive measurements, electron and hole collection networks can be visualized for the blends. The effect of additives on nanoscale morphology, charge generation and the device performance is also investigated. Films processed with additives results in a smaller degree of phase separation, and hence, higher interfacial areas for charge dissociation, while maintaining bicontinuous collection networks; conditions that lead to the high efficiency. An excellent agreement between nanoscale and bulk measurements is observed. The results demonstrate that pc-AFM is a powerful technique to characterize solar cell materials and can be used to understand the bulk performance.
Probing nanostructures and optoelectronic properties of bulk heterojunction solar cells processed with additives by photoconductive atomic force microscopy
Paper 7772-4 of Conference 7772
Date: Tuesday, 03 August 2010

Author(s): Thuc-Quyen T. Nguyen, Corey Hoven, Xuan-Dung Dang, Bright Walker, Chunki Kim, Guillermo C. Bazan, Univ. of California, Santa Barbara (United States)

Organic solar cells have obtained much attention in both academia and industry because they have the potential to produce low-cost plastic devices for alternative energy sources. In these devices, the performance depends strongly on the nanoscale film morphology and optoelectronic properties; therefore, it is important to control the nanoscale morphology and to probe these properties and correlate to the bulk measurements. Additives can be used to control the nanoscale morphology and the phase separation in bulk heterojunction solar cells. We combine dark and photoconductive atomic force microscopy (pc-AFM) to study nanoscale morphology and optoelectronic properties of bulk heterojunction solar cells based on low band gap conjugated polymers and [6,6] phenyl-C71-butyric acid methyl ester (PC71BM) system that was recently reported to have a power conversion efficiency over 5%. By controlling the applied voltage in photoconductive measurements, electron and hole collection networks can be visualized for the blends. The effect of additives on nanoscale morphology, charge generation and the device performance is also investigated. Films processed with additives results in a smaller degree of phase separation, and hence, higher interfacial areas for charge dissociation, while maintaining bicontinuous collection networks; conditions that lead to the high efficiency. An excellent agreement between nanoscale and bulk measurements is observed. The results demonstrate that pc-AFM is a powerful technique to characterize solar cell materials and can be used to understand the bulk performance.
Resistive switching behavior of ferroelectric tunnel junctions
Paper 7760-22 of Conference 7760
Date: Tuesday, 03 August 2010

Author(s): Alexei Gruverman, Univ. of Nebraska-Lincoln (United States)

In this work, we demonstrate the reproducible tunneling electroresistance effect in ultrathin ferroelectric heterostructures by means of scanning probe microscopy techniques. Ultrathin films of barium titanate (in the range from 2 nm to 10 nm) with microscopically patterned SrRuO3 and La0.67Sr0.33MnO3 (LSMO) top electrodes have been grown on the SrRuO3/SrTiO3 and LSMO/SrTiO3 substrates by atomic-layer-controlled pulsed-laser deposition. Nanoscale polarization detection and spatially-resolved polarization-dependent local conductance measurements in these heterostructures have been performed via Piezoresponse Force Microscopy (PFM) and Conducting Atomic Force Microscopy (C-AFM), respectively.
Glass-encapsulant interface characterization following temperature and humidity exposure
Paper 7773-37 of Conference 7773
Date: Wednesday, 04 August 2010

Author(s): Katherine M. Stika, Rebecca L. Smith, Donald Huang, Diane Davidson, James Marsh, Robert Agostinelli, John Wyre, DuPont Co. (United States)

The ability to optimize and consistently control the properties of the polymer-glass interface in thin film PV laminates in an important aspect of module reliability. Using variable rate peel delamination methods developed to isolate the encapsulant/glass interface, ion migration and interfacial chemistry have been studied following temperature and humidity exposure. In this presentation we will review quantitative AFM (Atomic Force Microscopy), XPS (X-ray Photoelectron Spectroscopy) and ToF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry) analyses linking failure modes with interfacial chemistry.
Nanosecond pulsed laser deposition of germanium films
Paper 7766-41 of Conference 7766
Date: Wednesday, 04 August 2010

Author(s): Seong Shan Yap, Norwegian Univ. of Science and Technology (Malaysia); Cécile Ladam, SINTEF (Norway); Wee Ong Siew, Multimedia Univ. (Malaysia); Øystein Dahl, SINTEF (Norway); Turid W. Reenaas, Norwegian Univ. of Science and Technology (Norway); Teck Yong Tou, Multimedia Univ. (Malaysia)

In this work, nanosecond-pulsed of from ultra-violet to infrared lasers: KrF (248 nm, 25 ns) and Nd:YAG (1064 nm, 532 nm, 355 nm, 5 ns) were employed for ablation and deposition of germanium films in background pressure of <10-6 Torr. Deposition was carried out at room temperature on Si, GaAs, sapphire and glass. The as-deposited films, characterized by using scanning electron microscopy (SEM) and atomic force microscopy (AFM), consists of nano to micron-sized droplets on nanostructured film. The dependence of films properties on laser wavelengths and fluence is discussed.
Rubrene electronic structure, interface energy level alignment, and growth dynamics
Paper 7778-18 of Conference 7778
Date: Monday, 02 August 2010

Author(s): Huanjun Ding, Yongli Gao, Univ. of Rochester (United States)

We have investigated the electronic structure, interface formation, and thin film growth dynamics of rubrene using ultraviolet photoemission spectroscopy (UPS), inverse photoemission spectroscopy (IPES), angle-resolved photoemission spectroscopy (ARPES), and atominc force microscopy (AFM). From UPS and IPES we obtained an injection gap of 2.67 eV and a transport gap of 3.98 eV. The ARPES results indicate that the HOMO band dispersion is about 0.25 eV, which leads to an estimate of the hole mobility of 15 Vs/cm2. The investigation of the electronic structure of the interfaces between rubrene and various metals shows that the Fermi level shifts linearly within the band gap as a function of metal workfunction, until it is been pinned at the LUMO by a low workfunction metal like Ca. The growth morphology dependence on the film thickness, deposition rate, and substrate temperature will also be discussed.
Atmospheric pressure plasma jet cleaning of carbon contaminated synchrotron optics
Paper 7794-33 of Conference 7794
Date: Monday, 02 August 2010

Author(s): J. Y. Yuh, C. I. Ma, Bor-Yuan Shew, National Synchrotron Radiation Research Ctr. (Taiwan); Peter Pai, Suntex Fiber Co., Ltd. (Taiwan); Jen-You Chu, Industrial Technology Research Institute (Taiwan); Chyuan-Tsyr Tzeng, Lan Yan Institute of Technology (Taiwan); Harry Chen, Creating Nano Technologies, Inc. (Taiwan)

Carbon contaminated optics such as mirrors and gratings undergo severe flux loss after years' illumination by the focused synchrotron light. Low pressure plasma glow discharge (LPPGD) has been considered as a cost effective cleaning method. Recently, Atmospherically Pressure Plasma Jet (APPJ) cleaning of organic compound gains solid ground in the LCD industry. In its application to optics cleaning, our study showed not only overcome the disadvantage of vacuum operation but also very fast carbon removing rate. With further analysis of the surface micro-roughness variation by AFM, we could obtain the optimum conditions to perform the optics cleaning on the beamline.
Design and fabrication of super mirrors on the Zerodur substrate
Paper 7786-38 of Conference 7786
Date: Monday, 02 August 2010

Author(s): Hyun-Ju Cho, Daeduk College (Korea, Republic of); Sang-Hyun Lee, Pump-Sik Lee, Jae-Cheul Lee, Hanwha Corp. (Korea, Republic of)

Super mirror is a high reflectance mirrors and therefore it has very low absorption and scattering losses. We carefully measure the Zerodur substrate using phase shift interferometer and AFM and compared it to the scattering of the mirror. Also the absorption of the mirror was measured by ring down cavity method, and its results were correlated to the thin film fabrication conditions. To examine the plasma degradation, we exposure UV to the mirror and the absorption variation were monitored. And finally, we propose the super mirror fabrication conditions which include substrate roughness, mirror structure, and its fabrication methods.
Carbon nanotube applications to scanning probe microscopy for next generation semiconductor metrology
Paper 7767-15 of Conference 7767
Date: Tuesday, 03 August 2010

Author(s): Victor H. Vartanian, SEMATECH North (United States); Ilona L. Sitnitsky, Matthew D. Bresin, Univ. at Albany (United States); Joseph J. Kopanski, National Institute of Standards and Technology (United States); Philp D. Rack, Univ. of Tennessee (United States); Vladimir Mancevski, Paul F. McClure, Xidex Corp. (United States); Vincent P. Labella, Kathleen A. Dunn, Univ. at Albany (United States)

Scaling of CMOS transistors below the 100 nm channel length has led to shallower junctions and higher channel doping concentrations, requiring two-dimensional dopant profiling. Scanning probe microscopy (SPM) techniques have become extremely attractive because of high spatial resolution for probing electrical properties. However, metal-coated silicon tips can wear out during operation and have limited spatial resolution. Therefore, carbon nanotube (CNT)-based AFM probes are desirable because of their durability and smaller diameter. Carbon nanotube assemblies having reduced parasitic capacitance and resistance are used to measure two-dimensional dopant concentration profiles in patterned substrates, dielectric constant variation in samples exposed to various plasma processes, and work functions of high-k/metal gate film stacks.
Enhance of power conversion efficiency of pentacene/C60 photovoltaic device via annealing control
Paper 7777-81 of Conference 7777
Date: Wednesday, 04 August 2010

Author(s): Jia-Cing Huang, National Taiwan Univ. of Science and Technology (Taiwan); Yung-Ting Chang, Shun-Wei Liu, National Taiwan Univ. (Taiwan); Chih-Chien Lee, Wei-Cheng Su, National Taiwan Univ. of Science and Technology (Taiwan)

In this report, we study the influence of post annealing treatment to the device performance base on a pentacene (40 nm)/ fullerene (C60) (50 nm) hetero junction structure small molecule organic photovoltaic (OPV) device. The post annealing treatment was done in the nitrogen environment with a low temperature (50oC) and the electrical characteristic of the devices were measured every 24 hours. Compare with the device before thermal treatment, the series resistance of the device was decrease from 1.2K to 0.5K ohm and the shunt resistance was increase from 5.7K to 9.5K ohm, which result in a 32% enhancement of the fill factor (form 0.34 to 0.45) after 100 hours thermal treatment. At the same time, the open circuit voltage was also increase from 0.36 to 0.44V while the short circuit current remains approximately. Finally, the improvement of the power conversion efficiency form 0.64 to 1.11% was obtained. These results were attributed to the morphology change between the interface of pentacene/ C60 and C60/ Al, which were analyzed through atomic force microscopy (AFM) and photoluminescence (PL) measurement.
Hybrid nanostructured solar cells based on the incorporation of inorganic nanoparticles in polymer-fullerene mixtures
Paper 7772-54 of Conference 7772
Date: Wednesday, 04 August 2010

Author(s): Jilian N. de Freitas, Ana F. Nogueira, Univ. Estadual de Campinas (Brazil)

Ternary systems based on mixtures of P3HT, PCBM and inorganic nanoparticles such as CdSe, ZnS or InPAs were investigated. At the optimized materials concentration, the presence of the nanoparticles increased the photocurrent and the voltage, improving the efficiency of the devices. The light-absorption, emission, and charge transport properties were modulated by changing the size/chemical composition/dopping degree of these nanoparticles and their effects on the performance of the solar cells were analyzed. A complete study on the morphology effects induced by the presence of these nanoparticles was also performed, using AFM, HR-TEM and optical microscopy techniques.
Molecular beam epitaxial growth of self assembled multilayer In(Ga)As/GaAs quantum dot heterostructures on germanium substrate
Paper 7768-21 of Conference 7768
Date: Wednesday, 04 August 2010

Author(s): Sreetama Banerjee, Indian Institute of Technology, Bombay (India)

Optimized growth of III-V semiconductors on Germanium (Ge) substrate offers opportunities of integrating III-V optoelectronics with Silicon. We have reported the growth of multilayer S-K grown In(Ga)As/GaAs QDs on Ge, with a Migration Enhanced Epitaxy grown GaAs layer followed by a slow growth rate (0.1µm/h) GaAs layer between the GaAs and Ge substrate. AFM shows formation of QDs with density of ~10^11 cm^-2. XTEM shows the heterostructure is defect free. Photoluminescence (PL) spectrum exhibits a peak at 1051nm with a FWHM of ~55meV, which is comparable to a control sample grown on GaAs substrate. Acknowledgement: DST India, SPM IIT-Bombay.
Nanostructure control and morphology of the fabricated active layer by poor solvent
Paper 7777-48 of Conference 7777
Date: Wednesday, 04 August 2010

Author(s): Shizuyasu Ochiai, Daichi Yamanaka, Kenzo Kojima, Aichi Institute of Technology (Japan)

After a bulk-hetero junction structure was adopted for the structure of an organic solar cell, the organic solar cell of a power conversion efficiency exceeding 6% was developed. In the thin film fabricated by a 0.5%wt-Poly(3-hexylthiophene)[P3HT] chloroform-solution added poor-solvent ethanol, P3HT grains were found. Moreover, the thin film fabricated by 0.5wt%-PCBM {[6,6]-Phenyl-C61-Butyric Acid Methyl Ester} chloroform-solution added with poor solvent ethanol was formed by PCBM aggregations. In the thin film fabricated by the 0.5%wt-P3HT/0.5%wt-PCBM chloroform-solution added with poor solvent ethanol, an interpenetrating network will be formed. Therefore, the shape and morphology of the grains of P3HT and PCBM are investigated by AFM images and UV/vis spectra.
Photocurrent generation in electrostatic layer-by-layer films based on PPV and single wall carbon nanotubes
Paper 7777-90 of Conference 7777
Date: Wednesday, 04 August 2010

Author(s): Luiz Carlos P. Almeida, Univ. Estadual de Campinas (Brazil); Valtencir Zucolotto, Univ. de São Paulo (Brazil); Ana F. Nogueira, Univ. Estadual de Campinas (Brazil)

Thin films based on electron-donating and electron-accepting organic materials have been widely investigated as candidate materials for applications in electronic devices. In this work, we will discuss the application of LBL technique to fabricate multilayer thin films based on poly(p-phenylenevinylene) (PPV) and carboxylic acid functionalized single wall carbon nanotubes (SWCNTs-COOH). The LBL films were investigated by UV-Vis and PL spectroscopy and also by AFM aiming to demonstrate the incorporation of SWCNTs onto PPV blocks. Photoelectrochemical experiments confirm charge transfer from PPV to SWCNT through photocurrent generation obtained from on-off cycles of illumination.
An apertureless near-field scanning optical microscope for imaging surface plasmons in the mid-wave infrared
Paper 7787-27 of Conference 7787
Date: Thursday, 05 August 2010

Author(s): John Kohoutek, Ryan Gelfand, Dibyendu Dey, Hooman Mohseni, Northwestern Univ. (United States)

We present an experimental technique for imaging surface plasmons in the mid-wave infrared region. The near field scanning optical microscope (NSOM) involves reflecting light from an edge emitting quantum-cascade-laser off of a metal coated atomic force microscope tip and then going back through the laser. We use a lock-in amplifier to lock to the harmonics of the AFM tip vibration frequency. This setup has topographic imaging in parallel with the infrared near-field such that the active source can easily be found. Detailed will be our experimental setup and results, with applications in biosensing, chemical sensing, plasmonic characterization, and laser diagnostics.
Fabrication of nanostructured aluminium thin film and in-situ monitoring of the growth
Paper 7766-32 of Conference 7766
Date: Thursday, 05 August 2010

Author(s): Michal Novotny, Jiri Bulir, Jan Lancok, Petr Pokorny, Institute of Physics of the ASCR, v.v.i. (Czech Republic)

Ultra thin nanostructured metal films exhibit unusual properties and performances. Film functional properties depend strongly on the nanostructure that can be manipulated by varying nucleation and growth conditions. Hence, in order to control the nanostructure of aluminium thin film fabricated by magnetron sputtering, we focus on in-situ monitoring of electrical conductivity and optical reflectivity of the growing layer as well as plasma characterization. The results of the in-situ monitoring are correlated with the AFM and SEM analyses. We demonstrate the monitoring can distinguish the growth mode in the real-time. We can estimate the point of coalescence of the growing layer and control the layer roughness.
In situ probing thickness dependence of the field effect mobility of naphthalenetetracarboxylic diimide-based field-effect transistors
Paper 7778-32 of Conference 7778
Date: Tuesday, 03 August 2010

Author(s): Shun-Wei Liu, National Taiwan Univ. (Taiwan); Chih-Chien Lee, Hung-Lin Tai, Je-Min Wen, National Taiwan Univ. of Science and Technology (Taiwan); Jiun-Haw Lee, National Taiwan Univ. (Taiwan); Chin-Ti Chen, Academia Sinica (Taiwan)

The fundamental limits of the charge mobility of organic semiconductors depend on an optimal -orbital overlap between semiconducting molecules, which is in turn controlled by the fashion of molecular packing or ordering. Thus, probing the charge transport characteristics of the first few monolayers (MLs) in organic field-effect transistors (OFETs) is essential in understanding the thickness dependence of OFET performance. In this letter, we present an in situ vacuum measurement in the study of electrical characteristics of n-channel OFETs based on NTCDI-C8F15 n-type semiconductors. Electron mobility of NTCDI-C8F15 OFETs was estimated as a function of the number of ML and its surface coverage using in situ electrical measurement. The electron mobility has been observed for the thin film transistor of NTCDI-C8F15 as thin as 2 ML (~ 5 nm). Field-effect mobilities rapidly increases with the increase of the film thickness and the surface coverage. Electron mobility of OFETs reaches saturation thickness (d0) about 5 ML and the surface coverage of the thin film becomes fullfilled around 3 ML. Our experimental results indicated that the molecular layers beyond d0 contribute little to the carrier transport in the semiconducting channel. The atomic-force microscopy (AFM) images of the NTCDI-C8F15 layer revealed the layer-plus-island (Stranski-Krastanov mode) growth mechanism. X-ray diffraction was used to identify the morphology of the packing structure of NTCDI-C8F15 during the growth of thin films. Our experimental results have demonstrated that the grown fashion of the first few ML of NTCDI-C8F15 on the substrate strongly influences the thin film surface morphology, packing structure, and carrier mobility.
Solution processed hybrid photovoltaics: the preparation of a standard ZnO template (Oral Standby)
Paper 7777-73 of Conference 7777
Date: Wednesday, 04 August 2010

Author(s): Jonathan Downing, Mary P. Ryan, Natalie Stingelin-Stutzmann, Martyn A. McLachlan, Imperial College London (United Kingdom)

There is increasing interest in the development of low-cost, solution processable photovoltaic devices. Device heterostructures with nanostructured interfaces between inorganic and organic materials, so-called 'hybrid cells', have the potential to achieve improved efficiency whilst minimizing both material and processing costs. A hybrid cell is advantageous as it combines the desirable properties of each constituent. For example metal oxides, and in particular ZnO, have high electron mobilities and can be prepared with numerous morphologies. Furthermore, solution processing permits the formation of ZnO structures with feature sizes ranging from a few nanometres to tens of microns over large areas. For organic materials, and in particular poly(3-hexylthiophene)(P3HT), excellent hole transport properties are combined with strong light-absorption. Compatibility with solution processing is well documented for this material. We will report our initial studies, which focus on the identification of a reproducible route for the formation of a standard nanostructured ZnO template. We outline our progress towards the synthesis of ZnO nanorods of controlled dimensions directly on ITO coated glass and on continuous layers of ZnO. The influence of the precursor solution, growth conditions and substrate on the aspect ratio, density and quality of the films prepared will be discussed. Our methodology allows the reproducible formation of ZnO nanostructures engineered increase interfacial area in hybrid devices. We will present SEM, AFM and XRD characterisation of the structures and correlate the film structure with processing conditions.

Fabrication of Raman biochip prototype by femtosecond laser micromachining
Paper 7759-42 of Conference 7759
Date: Tuesday, 03 August 2010

Author(s): Zenghui Zhou, Jian Xu, Fei He, Yang Liao, Ya Cheng, Zhizhan Xu, Shanghai Institute of Optics and Fine Mechanics (China); Koji Sugioka, Katsumi Midorikawa, RIKEN (Japan)

A nanoscale surface-enhanced Raman scattering (SERS) substrate is fabricated by fs laser reduction and deposition. The conductive silver microstructures are also deposited in fs laser irradiated area on the glass surfaces. Based on this approach, we integrate the microelectronic circuit and micro-Raman substrate into a microfluidic chamber and form a prototype of Raman biochip for biosensing. Enhancement of Raman signal and control of temperature of the sensor are both achieved. This technique provides a great potential for integrating microelectronics and micro-Raman sensors on a single glass chip.l>
Instrument and materials development in Raman spectroscopy detection and imaging techniques for supporting planetary exploration
Paper 7819-10 of Conference 7819
Date: Wednesday, 04 August 2010

Author(s): Bin Chen, NASA Ames Research Ctr. (United States)

Our research focuses on laboratory development of ultra sensitive Raman spectroscopy detection and imaging techniques for organic constituents and biomarkers in planetary explorations. Surface enhanced Raman spectroscopy (SERS) substrates including oriented bundles of Ag nanowires were created using the Langmuir-Blodgett technique. Raman imaging of these films revealed the overall distribution of the SERS effect of R6G. Raman imaging showed the distribution of hotspots on the nanowire bundles that significantly improves the sampling sensitivity and imaging capability for heterogenous field samples.
Towards advanced biological detection using surface enhanced Raman scattering (SERS)-based sensors
Paper 7759-17 of Conference 7759
Date: Sunday, 01 August 2010

Author(s): Mikella E. Hankus, Dimitra N. Stratis-Cullum, Paul M. Pellegrino, U.S. Army Research Lab. (United States)

No abstract available
Highly sensitive surface-enhanced Raman scattering substrate made from super-aligned carbon nanotubes
Paper 7761-16 of Conference 7761
Date: Monday, 02 August 2010

Author(s): Yinghui Sun, Kai Liu, Zheyao Wang, Kaili Jiang, Shoushan Fan, Tsinghua Univ. (China)

Surface-enhanced Raman scattering has attracted wide attention because it can enhance normally weak Raman signal by several orders of magnitude, and facilitate the sensitive detection of molecules. Conventional SERS substrates are constructed by placing metal nanoparticles on a planar surface. Here we show that, if the planar surface was substituted by a unique nanoporous surface, the enhancement effect can be dramatically improved. The nanoporous surface can be easily fabricated in batches and at low costs by cross stacking super-aligned carbon nanotube films. The as-prepared transparent and freestanding SERS substrate is capable of detecting ambient trinitrotoluene vapor, showing much higher Raman enhancement than ordinary planar substrates because of the extremely large surface area and the unique 0D@1D nanostructures. These results not only provide a new approach to ultrasensitive SERS substrates, but also are helpful for improving the fundamental understanding of SERS phenomena.
Physics and fabrication of novel surface enhanced Raman scattering substrates
Paper 7757-23 of Conference 7757
Date: Monday, 02 August 2010

Author(s): Kenneth B. Crozier, Harvard University (United States)

We report two methods for improving the performance of surface-enhanced Raman scattering (SERS) substrates. In the first, we describe a substrate with plasmon resonances at both excitation and Stokes frequencies (ACS Nano, in press). This multi-layer structure combines localized surface plasmons on nanoparticles with surface plasmon polaritons excited on a gold film (Opt. Lett. 34, 244 (2009)). We also describe related work on nanorings for SERS (Opt. Lett. 35, 760 (2010)), and on narrow surface plasmon resonances (APL 34, 244 (2009)). In the second method, we present a means for fabricating optical antennas with sub-10nm gaps using a sacrificial layer.
Surface-enhanced Raman scattering characterization of Ag nanorod arrays fabricated by oblique angle deposition
Paper 7757-22 of Conference 7757
Date: Monday, 02 August 2010

Author(s): Yiping Zhao, Y.-J. Liu, The Univ. of Georgia (United States)

No abstract available
Near-infrared surface enhanced Raman spectroscopy on single copper nanowire decorated with gold nanoparticles
Paper 7764-32 of Conference 7764
Date: Wednesday, 04 August 2010

Author(s): Roshan Guttikonda, Lihua Qian, Biswajit Das, Univ. of Nevada, Las Vegas (United States)

Copper nanostructures are promising for the development of near-infrared SERS substrates with the potential for reduced laser-induced degradation of probe molecules. In this work, an individual copper nanowire conjugated with gold nanoparticles shows significant enhancement of Raman signal with a factor of 6x104 times compared to a single copper nanowire. The enhancement primarily results from near field electromagnetic coupling confined within the tiny crevices between nanowire and nanoparticles. The excellent properties of these structures make them promising for the development of low-cost and reliable near-infrared SERS substrates with potential applications in biological sensors and disease diagnosis.
Remote-Raman spectroscopy of optically trapped particles by utilizing a hollow optical fiber
Paper 7762-127 of Conference 7762
Date: Wednesday, 04 August 2010

Author(s): Takashi Katagiri, Yoshitake Morisaki, Yuji Matsuura, Tohoku Univ. (Japan)

The fiber-optic probe based on a hollow optical fiber was developed for highly-sensitive remote-Raman measurements of particles in solution. A lens mounted at the distal end of the fiber was optimally designed to suppress the spherical aberration and maximize the numerical aperture by a ray-optics method, and fabricated by polishing a SrTiO3 ball (n = 2.4) of 1 mm diameter. Polystyrene particles of 60 microns diameter dispersed in NaCl aqueous solution were three-dimensionally trapped by the prototype probe. The Raman spectrum of the polystyrene particle was clearly observed when the particle was optically trapped at the beam focus.
Optical properties and surface-enhanced Raman scattering of quasi-3D gold plasmonic nanostructures
Paper 7757-66 of Conference 7757
Date: Thursday, 05 August 2010

Author(s): Qiuming Yu, Jiajie Xu, Univ. of Washington (United States)

Recently, we developed a unique quasi-3D plasmonic nanostructure composed of a thin metal film with nanoholes on top and metal disks at the bottom of each well. The plasmonic and optical properties of the quasi-3D plasmonic crystals were studied via the measurement of the normal transmission and dark field scattering spectroscopy and the three-dimensional finite-difference time-domain (3D-FDTD) calculations. The nanofabrication of these quasi-3D plasmonic nanostructures via EBL and soft lithography and the applications of SERS using these nanostructures as substrates in directly detecting cancer genes and single bacterial cells will be discussed.
ExoMars Raman Laser Spectrometer overview
Paper 7819-40 of Conference 7819
Date: Thursday, 05 August 2010

Author(s): Andoni G. Moral, Carlos Pérez, Instituto Nacional de Técnica Aeroespacial (Spain)

The Raman Laser Spectrometer (RLS) is one of the Pasteur Payload instruments, within the ESA's Aurora Exploration Programme, ExoMars mission. The RLS Instrument will perform Raman spectroscopy on crushed powered samples deposited on a small container after crushing the cores obtained by the Rover's drill system. The RLS instrument will be accommodated and operate inside the Rover's ALD (Analytical Laboratory Drawer) using the internal optical head, complying with COSPAR Planetary Protection requirements. The RLS Instrument is composed by the following units: SPU (Spectrometer Unit) iOH: (Internal Optical Head): ICEU (Instrument Control and Excitation Unit) Other instrument units are EH (Electrical Harness), OH (Optical Harness) and SW.
Plasmo-photonic nanowire arrays for large-area surface-enhanced Raman scattering sensors
Paper 7757-72 of Conference 7757
Date: Thursday, 05 August 2010

Author(s): Joshua D. Caldwell, Orest J. Glembocki, Ronald W. Rendell, Sharka M. Prokes, James P. Long, U.S. Naval Research Lab. (United States)

Here we have fabricated large arrays (>10um) of Ag- and Au-coated vertical semiconductor nanowire and nanorods to investigate plasmonic and photonic interactions and the influence on the SERS intensity. While the overall SERS intensity from a monolayer of benzene thiol on the arrays increased in amplitude with shrinking nanorod diameter, the SERS intensity also exhibited periodic behavior characteristic of diffraction (pitch/). Calculations of the electromagnetic field within such arrays enabled direct comparison to the experiments. The calculations agree well with experiments, illustrating long-range photonic coupling between small diameter nanostructures leading to further increases in the SERS enhancement factors.
Characterization of m-plane ZnO thin film on (112)LaAlO3 by pulsed laser deposition
Paper 7766-2 of Conference 7766
Date: Wednesday, 04 August 2010

New Hatteras femtosecond transient absorption system
Photon Scanning Tunneling Microscope - Power Point presentation (use read-only mode)
Atomic Force Microscope AFM HERON - sample quotes
Near-field Scanning Optical Microscope (NSOM) for nano-characterization and nanomanufacturing

Author(s): Hsin-Hua Wang, Cheng-Ying Chen, National Taiwan Univ. (Taiwan); Jr-Sheng Tian, National Chiao Tung Univ. (Taiwan); Yu-Cheng Yeh, National Taiwan Univ. (Taiwan); Ying-Hao Chu, Li Chang, National Chiao Tung Univ. (Taiwan); Miin-Jang Chen, Yuh-Renn Wu, Jr-Hau He, National Taiwan Univ. (Taiwan)

In our study, X-ray diffraction, Raman, and photoluminescence (PL) spectra of the m-plane ZnO film grown on (112)LaAlO3 (LAO) substrate by pulsed laser deposition has been investigated. The Raman spectra show that the films are under tensile strain. Polarized Raman spectra and polarized PL spectra were investigated to characterize the optical anisotropy of on the m-plane ZnO/LAO. The intensity of E2(high) mode in Raman spectra is strongly polarization-dependent. PL spectra also exhibit optical anisotropy in the m-plane ZnO films, which can be attributed to the selection rule in different exciton transitions in ZnO.
Mechanistic studies into the Raman enhancement of enediol-semiconducting nanoparticle conjugates and their use in biological applications
Paper 7758-14 of Conference 7758
Date: Wednesday, 04 August 2010

Author(s): Sarah J. Hurst, H. Christopher Fry, David J. Gosztola, Argonne National Lab. (United States); Daniel Finkelstein-Shapiro, Northwestern Univ. (United States); Vladimiro Mujica, Arizona State Univ. (United States); Tijana Rajh, Argonne National Lab. (United States)

Recently, we have found that enediol-labeled semiconducting nanoparticles (TiO2 nanoparticles, ~ 5 nm in diameter) exhibit enhanced Raman signatures compared to that of the enediol molecules alone (~ 3 orders of magnitude higher). The existence of a charge-transfer (CT) complex between the nanoparticle and the organic ligand, where electrons and holes localize on the nanoparticle and ligand, respectively, is a necessary requirement for this enhancement. Herein, we explore the mechanism by which particular Raman modes are enhanced or suppressed in this system by tuning parameters, including the chemical composition of the nanoparticle and ligand. Further, we explore the origin of the enhancement by investigating, both experimentally and theoretically, the nanoparticle size-dependant saturation effect (the Raman intensity decreases at higher ligand surface coverage) that is observed. Raman enhancement also is seen for biomolecule-nanoparticle conjugate structures, where the biomolecules (e.g., peptides) are linked to the surface of the particle through a catechol linker. Finally, we show how the chemical and physical properties of these novel nanoparticle materials can be tailored for use in biodetection and energy storage/transduction strategies.
Fundamental limit of nanophotonic light-trapping in solar cells
Paper 7772-33 of Conference 7772
Date: Wednesday, 04 August 2010

Author(s): Zongfu Yu, Aaswath P. Raman, Shanhui Fan, Stanford Univ. (United States)

The limit of enhancement factor for light-trapping in nanophotonic structure is calculated. The limit is found to be much larger than the conventional bulk limit of 4n^2. This opens new avenues for highly efficient next-generation solar cells.
Study of metal nanoparticle assembly for the optimization of SERS enhancements
Paper 7757-137 of Conference 7757
Date: Monday, 02 August 2010

Author(s): Bryan Paladini, Paul R. Mark, Laura Fabris, Rutgers, The State Univ. of New Jersey (United States)

Raman spectroscopy has been historically known for having very low cross sections: However, in the presence of metal nanoparticles (NPs) whose sizes are smaller than the wavelength of the incident light, the excitation of the surface plasmon allows for an unprecedented electromagnetic field enhancement in close proximity to the metallic surface. As a consequence, the Raman signal experiences enhancements up to 10-12 orders of magnitude, a phenomenon known as surface enhanced Raman scattering (SERS).1 It has been shown that the highest signal enhancement originates from assemblies of two NPs (dimers).2 In order to obtain such enhancements and to avoid the formation of higher order aggregates it is necessary to control the NP assembly. Moreover, being SERS highly distant dependent, it is necessary to lock the NPs at a very specific distance. Thus it is necessary to determine methods that optimize the formation of dimers at the expense of bigger aggregates, and that allow the systems to be stable in different types of solvents. Herein we describe our approach for the synthesis and stabilization of metal NP dimers that are capable of optimizing the SERS signal enhancement. Gold and silver NPs of different sizes and shapes (e.g. spheres, rods, cubes, plates) are synthesized and their controlled assembly into dimers via use of di-functionalized small molecular linkers is studied. Moreover, simulations are carried out to determine the dynamics of dimer formation and its dependence on the concentration of the NPs, their shape, and the properties of the capping agents. [1] K.A. Willets, R.P. Van Duyne, Annu. Rev. Phys. Chem. 2007, 58, 267. [2] M. Moskovits, J. Raman Spectrosc. 2005, 36, 485.
SERS from ellipsoidal nanoparticles
Paper 7757-134 of Conference 7757
Date: Monday, 02 August 2010

Author(s): Gautam Mukhopadhyay, Indian Institute of Technology, Bombay (India); Shruti R. Puri, Stanford Univ. (United States); Pragati Mukhopadhyay, Indian Institute of Technology, Bombay (India)

We present here a mathematical formulation determining the enhancement factors of Raman scattered light from molecules adsorbed on to multiply coated ellipsoidal particles. We use this formulation to present enhancement of Raman scattering from molecules, such as pyridine and CV from nanoparticles of gold and silver as well as their core-shell structures with magnetic metal cobalt. The nanoparticles of these metals are widely used in biomedical applications. We also present results for the cases when the nanoparticle is covered with a monolayer of Raman active molecules and dispersed randomly in a medium. Our results can be of importance in medical technology.
Engineering aperiodic order for optical devices with photonic-plasmonic nanostructures
Paper 7755-6 of Conference 7755
Date: Sunday, 01 August 2010

Author(s): Luca Dal Negro, The Boston Univ. Photonics Ctr. (United States)

Deterministic Aperiodic Structures (DAS) are generated by the mathematical rules of L-systems and number theory, manifest unique light localization and transport properties associated with a great structural complexity, and can be fabricated on-chips using conventional nano-lithographic techniques. When combined with metal-dielectric nanostructures, they give rise to large energy gaps like periodic media (i.e. photonic-plasmonic crystals) and highly localized, enhanced field states like disordered random media, including the formation of Anderson-localized modes, forbidden in periodic scattering media. Contrary to random media, DAS possess controllable transport properties from ballistic to anomalous diffusion (slower diffusion than classical random walks) and strongly localized field states with large fluctuations of the photonic mode density - essential attributes to achieve spatio-temporal energy localization and enhanced light-matter coupling, i.e. radiative rates of fluorescent molecules, absorption cross-sections, non-linear optical processes on the nanoscale. In particular, DAS fabricated using metal/dielectric nanoparticles are suitable to engineer efficient nanoplasmonic structures for Surface Enhanced Raman (SERS) sensing, optical detectors, and enhanced light-emitting and nonlinear components. In this talk, by combining dark-field scattering characterization, micro-photoluminescence and Raman measurements with accurate electrodynamics calculations based on semi-analytical multiple-scattering theories, I will discuss electromagnetic coupling1,2, resonant scattering3, colorimetric biosensing4, light emission5 and surface enhanced Raman sensing6,7 in two-dimensional metal-dielectric photonic-plasmonic arrays based on deterministic aperiodic sequences. In particular, I will survey the optical properties, and assess the device performances, of different aperiodic systems ranging from quasi-periodic crystals to pseudo-random nanoparticle arrays8 fabricated by Electron-Beam Lithography (EBL) on transparent quartz substrates. Finally, I will present novel aperiodic optical nano-antennas structures that can provide strong field localization at multiple frequencies over a broad spectral range9. References: 1. L. Dal Negro, N.N. Feng, A. Gopinath "Electromagnetic coupling and plasmon localization in deterministic aperiodic arrays", J. Opt. A: Pure Appl. Opt. 10, 064013 (2008) 2. C. Forestiere, G. Miano, G. Rubinacci, L. Dal Negro, "Analyis of localized modes and spectral gaps in Fibonacci arrays of metal nanoparticles", Phys. Rev. B., 79, 085404 (2009) 3. A. Gopinath, S. Boriskina, N.N. Feng, B.M. Reinhard, L. Dal Negro, "Photonic-plasmonic scattering resonances in deterministic aperiodic structures", accepted for publication in Nanoletters 8, 2423 (2008) 4. S. Boriskina, L. Dal Negro "Sensitive label-free biosensing using critical modes in aperiodic photonic structures", Optics Express, 16, 12511 (2008) 5. A. Gopinath, S. Boriskina, S. Yerci, R. Li, L. Dal Negro, Enhancement of the 1.54μm Erbium emission from quasi-periodic plasmonic arrays , Appl. Phys. Lett., 96, 071113 (2010) 6. A. Gopinath, S. Boriskina, B. Reinhard, L. Dal Negro, "Deterministic Aperiodic Arrays of Metal nanoparticles for surface-enhanced Raman scattering", Optics Express, 17, 3741 (2009). 7. A. Gopinath, S. Boriskina, W. Premasiri, L. Ziegler, B. Reinhard, L. Dal Negro, "Plasmonic Nanogalaxies: multi-scale aperiodic arrays for surface enhanced Raman sensing", Nanoletters 9, 3922 (2009) 8. C. Forestiere, G.F. Walsh, G. Miano, L. Dal Negro, "Nanoplasmonics of prime number arrays", Optics Express 17, 24289 (2009) 9. S. Boriskina, L. Dal Negro, "Multiple-wavelength plasmonic nano-antennas" Optics Letters, 35, 538, (2010).
Single-molecule and single-particle SERS (Keynote Presentation) (Keynote Presentation)
Paper 7757-17 of Conference 7757
Date: Monday, 02 August 2010

Author(s): Richard P. Van Duyne, Northwestern Univ. (United States)

The grand challenge of plasmonics is to control and manipulate light on the nanometer length scale. An improved understanding of the interactions between adsorbed molecules and plasmonic nanostructures (i.e., molecular plasmonics) is having a significant impact in many areas of plasmonics research including surface-enhanced Raman spectroscopy (SERS), new materials, optical microscopy, localized surface plasmon resonance (LSPR) spectroscopy for chemical and biological sensing, and nanolithography. This lecture will cover recent developments from the Van Group in single-molecule surface-enhanced Raman spectroscopy (SMSERS), single particle surface-enhanced Raman spectroscopy (SPSERS) and the development of single nanoparticle LSPR spectroscopy spatially correlated with high resolution transmission electron microscopy (HRTEM). The existence of SMSERS has been proven employing a frequency-domain approach with two isotopologues of rhodamine 6G (R6G) or crystal violet (CV) that provide unique vibrational signatures. When an average of one molecule is adsorbed per Ag nanoparticle, only one isotopologue is typically observed under dry N2 environment. The frequency-domain proof was subsequently used to study the structure of SMSERS active nanoparticle assemblies by HRTEM and electrodynamics theory as well as to perform excitation spectroscopy measurements. Understanding the relationship between single particle structure and activity represents a significant challenge for the field of surface-enhanced Raman scattering (SERS). To this end, the structural and optical properties of SERS nanoantennas comprised of aggregated Au nanoparticles that are coated with organic reporter molecules and encapsulated by a SiO2 shell have been determined using correlated transmission electron microscopy (TEM), dark-field Rayleigh scattering microscopy, SERS, and finite element method (FEM) calculations. The results show that the distribution of SERS enhancement factors (EFs) for a structurally and optically diverse set of nanoantennas is remarkably narrow. The EFs are uncorrelated to aggregation state and localized surface plasmon resonance (LSPR), but are crucially dependent on the size of the interparticle gap. This study demonstrates that the creation of hot spots, where two particles are in sub-nanometer proximity or have coalesced to form crevices, is paramount to achieving maximum SERS enhancements. A wide-field localized surface plasmon resonance (LSPR) imaging method using a liquid crystal tunable filter (LCTF) is used to measure the scattering spectra of multiple Ag nanoparticles in parallel. This method provides the ability to characterize moving Ag nanoparticles by measuring the scattering spectra of the particles while simultaneously tracking their motion. Consequently, single particle diffusion coefficients can be determined. As an example, several single Ag nanoprisms are tracked, the LSPR scattering spectrum of each moving particle is obtained, and the single particle diffusion coefficient is determined from its trajectory. Coupling diffusion information with spectral information in real time is a significant advance and addresses many scientific problems, both fundamental and biological, such as cell membrane protein diffusion, functional plasmonic distributions, and nanoparticle growth mechanisms. ACKNOWLEDGMENTS This research was supported by the NSF (CHE-0414554 and CHE-0911145), the AFOSR/DARPA Project BAA07-61 (FA9550-08-1-0221), and the NSF MRSEC (DMR-0520513) at the Materials Research Center of Northwestern University. We thank the NUANCE Center at Northwestern University for providing access to the TEM.
Single molecule SERS: fundamentals and potential in sensing and analytics (Keynote Presentation) (Keynote Presentation)
Paper 7757-18 of Conference 7757
Date: Monday, 02 August 2010

Author(s): Katrin Kneipp, Harald Kneipp,

Detecting and identifying a single molecule as well as quantification of small amounts of matter by counting molecules represents the ultimate limit in chemical analysis and sensing. Tracking of single molecules and monitoring their structural changes offer far-reaching opportunities in many fields of research. Surface enhanced Raman scattering (SERS) has the potential to address these issues. This talk discusses single molecule SERS performed without additional contributions of "intrinsic" molecular resonance Raman enhancement of the target molecules and shows that SERS has capabilities to surpass fluorescence spectroscopy as a widely used spectroscopic single molecule tool.
Exploring the interaction of molecular and plasmonic resonances from a practical and rigorous theoretical perspective
Paper 7758-2 of Conference 7758
Date: Wednesday, 04 August 2010

Author(s): David J. Masiello, Univ. of Washington (United States)

Ever increasing experimental interest in a variety of plasmon-enhanced molecular spectroscopies has provided impetus for the development of a corresponding assortment of theoretical descriptions of these phenomena. Linear processes such as Raman and fluorescence have found their plasmon-enhanced analogs in surface-enhanced Raman scattering and surface-enhanced fluorescence; both are now realized in the extreme limit of single-molecule detection. And plasmon-enhanced versions of n-wave mixing and hyper-Raman scattering, as well as other nonlinear spectroscopies, are rapidly being explored as ultrasensitive probes of molecular structure complementary to those linear. Outside of the laboratory, the challenge remains to develop theories that are rich enough to account for the basic chemistry and physics relevant to each, yet are simultaneously practical enough to implement numerically for real systems of current experimental interest. In this talk I will discuss my recent work in this direction aimed at describing the interaction between a general quantum-mechanical molecular system and an arbitrary plasmon-supporting metallic nanoparticle aggregate described classically. I achieve this by rigorously mixing together elements of modern molecular-electronic structure theory with a computational continuum-electrodynamics treatment of the plasmonic and electromagnetic fields. Application to the modeling of recent experiments in the Van Duyne group at Northwestern University will be highlighted.
Evaluation of semiconducting/metallic ratio of single wall carbon nanotubes by absorption and resonant Raman scattering
Paper 7761-2 of Conference 7761
Date: Sunday, 01 August 2010

Author(s): Mun Seok Jeong, Gwangju Institute of Science and Technology (Korea, Republic of); Kyoung In Min, Gwangju Institute of Science and Technology (Korea, Republic of) and Chonbuk National Univ. (Korea, Republic of); Ki Kang Kim, Sungkyunkwan Univ. (Korea, Republic of); Myoung Kyu Oh, Gwangju Institute of Science and Technology (Korea, Republic of); Soo Bong Choi, Ajou Univ. (Korea, Republic of); Heesuk Rho, Chonbuk National Univ. (Korea, Republic of); Ha Jin Lee, Korea Basic Science Institute (Korea, Republic of); Kay Hyeok An, Jeonju Machinery Research Ctr. (Korea, Republic of); Young Chul Choi, Hanwha Nanotech (Korea, Republic of); Jong Hun Han, Korea Electronics Technology Institute (Korea, Republic of); Kyung Hui Oh, Korean Agency for Technology and Standards (Korea, Republic of); Young-Hee Lee, Sungkyunkwan Univ. (Korea, Republic of)

No abstract available
Cysteamine-coated Ag and Au nanoparticles for improved surface-enhanced Raman scattering from dinitrotoluene and drinitrotoluene
Paper 7757-10 of Conference 7757
Date: Sunday, 01 August 2010

Author(s): Orest J. Glembocki, Madhu Gowda, Steven Geng, Sharka M. Prokes, Nelson Y. Garces, Julie Cushen, Joshua D. Caldwell, U.S. Naval Research Lab. (United States)

Surface-enhanced Raman scattering (SERS) of trinitrotolunene (TNT) and other nitro-based explosives is important for the development of optical detection sensors. It has recently been shown that cysteamine, which contains amino functional groups, will attract nitro groups of TNT. In this paper, we report on the SERS from TNT absorbed on cysteamine-coated Au and Ag nanoparticles. The cysteamine adsorbs either vertically (trans) or nearly horizontally (Gausche). We find that the trans configuration provides the best template for SERS detection of TNT. These experiments compare well with DFT calculations of the cysteamine and TNT bonding and their adsorption on Au and Ag.
Lateral distribution of the degradation of encapsulants after different damp-heat exposure times investigated by Raman spectroscopy
Paper 7773-13 of Conference 7773
Date: Wednesday, 04 August 2010

Author(s): Cornelia Peike, Thomas Kaltenbach, Michael Köhl, Karl-Anders Weiss, Fraunhofer-Institut für Solare Energiesysteme (Germany)

PV modules are supposed to have a service lifetime of more than 20 years. For making reliable service life estimations, it is necessary to have a suitable degradation indicator as well as a non-destructive method for analyzing the materials changes over time during indoor testing. Since the polymeric encapsulation material often shows degradation effects, it is useful to investigate encapsulation degradation. PV modules with c-Si-cells were analyzed after up to 4000 h of damp-heat exposure with Raman spectroscopy. The results show significant differences in the materials degradation at different points above the cell and after the aging steps, respectively.
Modeling, fabrication and analysis of photopatterned polymer and nanosphere substrates for surface enhanced Raman spectroscopy studies
Paper 7766-26 of Conference 7766
Date: Wednesday, 04 August 2010

Author(s): Fernando A. Calzzani, Jr., Alabama A&M Univ. (United States); Aschalew S. Kassu, Alabama A&M Univ. (United States) and U.S. Army Research, Development and Engineering Command (United States); Anup Sharma, Alabama A&M Univ. (United States); Paul B. Ruffin, Christina L. Brantley, Eugene Edwards, U.S. Army Research, Development and Engineering Command (United States)

This paper reports on the use and results of Finite Dimension Time Domain (FDTD) computer simulations technique to investigate the effect of various substrate parameters on the intensity of SPR and the resultant SERS spectra. The substrates used in this study are various sizes of photopatterned polybutadiene substrates produced by UV-lithographic technique and gold nanosphere particles. To verify the results, standard analyte like R6G are employed. Series of measurements have been performed to evaluate the suitability of the technique in modeling the substrates' 'hot-spot' for electromagnetic enhancement in SERS signal as well as the appropriate resonant excitation wavelength.
Monitor dynamic processes of single spore germination and inactivation by moist heat using combination of optical trapping, Raman spectroscopy and quantitative differential interference contrast microscopy
Paper 7762-92 of Conference 7762
Date: Wednesday, 04 August 2010

Author(s): Pengfei Zhang, Lingbo Kong, East Carolina Univ. (United States); Peter Setlow, Univ. of Connecticut Health Ctr. (United States); Yong-Qing Li, East Carolina Univ. (United States)

Optical trapping, Raman spectroscopy and quantitative differential interference (DIC) were used to monitor the dynamic processes of single bacterial spore during germination and inactivation by moist heat. Major conclusion from these studies included the following: 1) the brightness of original DIC image of an individual dormant spore is proportional to the CaDPA level of that spore; 2) the rapid drop in the intensity of original DIC image precisely corresponds to the CaDPA release of the spore, both during germination and during heat inactivation, as revealed by Raman spectroscopy; 3) the correspondence between the intensity of DIC image and CaDPA release allows the observation of heterogeneity in kinetics of germination and heat inactivation of hundreds of individual spores adhered on a microscope coverslip. The time at which the spore's CaDPA was released completely (Trelease) varied significantly from spore to spore, although the time required for release of the majority of spores' CaDPA (ΔTrelease) was nearly a constant (~ 1.5 min) for all individual spores; 4) an integration algorithm was applied to the original DIC image, resulting in an image in which the intensity is linearly proportional to the phase of spore. And the reconstructed phase image exhibited the distributions of CaDPA and cortex within the spore as well as their kinetics during germination and heat inactication.

Visualization of two different forms of DNA on HOPG by STM
Paper 7765-22 of Conference 7765
Date: Thursday, 05 August 2010

Author(s): Takahide Yokoya, Hidemasa Usui, Hirokazu Sakamoto, Kenji Mizoguchi, Tokyo Metropolitan Univ. (Japan)

No abstract available
Supported Metal Particles: Electronic Structure, Reaction, and Photochemistry (Plenary)
Paper OP10PLS-204 of Conference OP10PLS
Date: Monday, 02 August 2010

Author(s): Hans-Joachim Freund, Fritz-Haber-Institut der Max-Planck-Gesellschaft (Germany)

The electronic structure of supported metal nanoparticles has been investigated using scanning tunneling microscopy and spectroscopy as well as x‐ray photoelectron spectroscopy. In particular, the optical properties of individual Ag, Au, and alloy clusters are probed with a photon STM. Both, dark and photochemistry of molecules on the particles is studied as a function of a number of parameters, including particle size, gas pressure, conductivity and chemical nature of the support.
An atomic scale study of the effect of Sb on the growth of III-V quantum dots
Paper 7768-13 of Conference 7768
Date: Monday, 02 August 2010

Author(s): Murat Bozkurt, Technische Universiteit Eindhoven (Netherlands)

The effect of Sb on the growth of III/V quantum dots has been investigated at the atomic scale with cross-sectional STM. Sb is used during capping in different ways for quantum dots grown with different techniques under different growth conditions and in different growth directions. We have observed that quantum dot erosion during capping, observed for InAs/GaAs and InAs/AlAs quantum dots, is completely suppressed when GaAsSb is used in the capping. Furthermore, soaking the quantum dots with Sb only prior to capping has turned out to be an alternative way of suppressing quantum dot erosion for InAs/InP and InAs/GaAs quantum dots while only a fraction of Sb is actually incorporated in the quantum dots. A big surprise was the observation of segmented InAs/GaSb/InP quantum dots where the bottom part exists of InAs and the top part of GaSb with a sharp transition between them. These quantum dots might have internal type II confinement for electrons and holes.
Synthesis of epitaxial graphene using laser decomposition of SiC
Paper 7761-19 of Conference 7761
Date: Monday, 02 August 2010

Author(s): Sangwon Lee, Stanford Univ. (United States); Michael Toney, SLAC National Accelerator Lab. (United States); Wonhee Ko, Heejoon Jung, Hari Manoharan, Robert Sinclair, Alberto Salleo, Stanford Univ. (United States)

We propose an alternative low-temperature, spatially controlled and scalable epitaxial graphene (EG) synthesis technique based on laser-induced surface decomposition of SiC. This technique is compatible and amenable to large-scale integration. Furthermore, laser synthesis of graphene offers the additional advantage of combining synthesis and patterning in one step as the process can be designed to form graphene devices in predetermined locations on the substrate. We confirm the formation of EG on SiC as a result of excimer laser irradiation by using various characterization techniques such as RHEED, Synchrotron X-ray, Raman, TEM and STM.

Brochures to present at the exhibition:

Product Data Sheets

Pulse strecher/compressor
Avoca SPIDER system
Buccaneer femtosecond fiber lasers with SHG Second Harmonic Generator
Cannon Ultra-Broadband Light Source
Cortes Cr:Forsterite Regenerative Amplifier
Infrared cross-correlator CCIR-800
Cross-correlator Rincon
Femtosecond Autocorrelator IRA-3-10
Kirra Faraday Optical Isolators
Mavericks femtosecond Cr:Forsterite laser
OAFP optical attenuator
Pearls femtosecond fiber laser (Er-doped fiber, 1530-1565 nm)
Pismo pulse picker
Reef-M femtosecond scanning autocorrelator for microscopy
Reef-RTD scanning autocorrelator
Reef-SS single shot autocorrelator
Femtosecond Second Harmonic Generator
Spectrometer ASP-100M
Spectrometer ASP-150C
Spectrometer ASP-IR
Tamarack and Buccaneer femtosecond fiber lasers (Er-doped fiber, 1560+/- 10nm)
Teahupoo femtosecond Ti:Sapphire regenerative amplifier
Femtosecond third harmonic generator
Tourmaline femtosecond fiber laser (1054 nm)
Tourmaline TETA Yb femtosecond amplified laser system
Tourmaline Yb-SS femtosecond solid state laser system
Trestles CW Ti:Sapphire laser
Trestles femtosecond Ti:Sapphire laser
Trestles Finesse femtosecond lasers system integrated with DPSS pump laser
Wedge Ti:Sapphire multipass amplifier

Multi-terawatt lasers overview
Hydrogen Thyratrons - Deuterium Thyratrons - Untriggered Spask Gaps - Triggered Spask Gaps - X-ray tube
Rincon 800 third-order scanning cross-correlator for aligning 20 Terawatt Ti:Sapphire laser
MCP + phosphorous screen for imaging of XUV radiation (14eV- 160-eV) in high harmonics experiments
Femtosecond autocorrelator Reef-RTD 700-1300 nm
New Trestles fs/CW laser system which can be easily switched from femtosecond mode to CW and back.
Femtosecond Two-stage Amplifier System Wedge-XL (table-top terawatt system) - pdf
CORTES-800 40 TERAWATT LASER SYSTEM
New Beacon Femtosecond Fluoresscence Upconversion System
Tamarack C1560 femtosecond fiber laser
Pacifica THz Time Domain Spectrometer
Wedge TiSapphire Multipass Amplifier
New Hatteras femtosecond transient absorption system
Photon Scanning Tunneling Microscope - Power Point presentation (use read-only mode)
Atomic Force Microscope AFM HERON - sample quotes
Near-field Scanning Optical Microscope (NSOM) for nano-characterization and nanomanufacturing
Yb-based high-energy fiber laser system kit, model Tourmaline Yb-ULRepRate-07
Ytterbium-doped Femtosecond Solid-State Laser Tourmaline Yb-SS400
Pismo pulse picker for 1500-1600nm range

Del Mar Photonics Product brochures - Femtosecond products data sheets (zip file, 4.34 Mbytes) - Del Mar Photonics

Program and Notes