Del Mar Photonics

Optics and Photonics Presentations attended by Del Mar Photonics team.

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Atomic Force Microscope AFM HERON - sample quotes
Near-field Scanning Optical Microscope (NSOM) for nano-characterization and nanomanufacturing

Self-assembled monolayer and its wearing behavior on AFM probes
Paper 7405-34 of Conference 7405
Date: Wednesday, 05 August 2009
Time: 5:30 PM

Author(s): Cheng-Hsien Chen, Hao-Chih Liu, Wen-Dung Hsu, National Cheng Kung Univ. (Taiwan)

In this paper, we extended the prior work on wear resistant coatings of CD AFM probes to general AFM probes. Unlike prior studies on AFM tip coatings, the wearing and tip-sample interaction behavior of SAM coatings will be investigated by AFM, SEM, and TEM characterizations. In addition, we apply molecular dynamics (MD) and atomic-level simulation to model the nanotribological phenomena of SAM material in the vicinity of tip apex region. The MD simulations also provide models of the coating conformity at the AFM tip apex. We will discuss the relationships between SAM molecules and their adhesion and wear performance on AFM tips, and suggest wear-resistant probe designs for generic and special AFM/CD AFM applications.

AFM measurement of long-range quantum forces
Paper 7400-35 of Conference 7400
Date: Tuesday, 04 August 2009
Time: 10:50 AM – 11:20 AM

Author(s): Jeremy Munday, California Institute of Technology (United States)

Since its development, atomic force microscopy (AFM) has been an excellent tool for determining the surface properties of materials (e.g. topography, thermal and charge distributions, sample-tip forces, etc). For most situations, extremely sharp tips are used to increase lateral resolution; however, the reduced area of interaction between the tip and the sample results in a reduced sensitivity to long-range surface forces. Here I will describe the use of AFM to measure long-range surface forces between a sphere and a plate. In particular, I will show how the Casimir force, a force that results from the quantum mechanical zero-point energy of electromagnetic fields, can be measured using AFM. Despite its quantum origin, the Casimir effect can be felt in many macroscopic, natural phenomena and should be considered whenever sub-micron distances separate bodies. I will further show how this force, which depends only on the optical properties of materials, can be changed from attractive to repulsive by judicious choice of material bodies separated by fluid.

Independent measurements of an AFM tip's absolute z-position and applied force
Paper 7405-15 of Conference 7405
Date: Tuesday, 04 August 2009
Time: 3:50 PM – 4:10 PM

Author(s): Thomas T. Perkins, Gavin M. King, Allison B. Churnside, Univ. of Colorado at Boulder (United States)

Drift in atomic force microscopy is a longstanding problem. By scattering lasers off the tip and a fiducial mark in the sample, we locally measure and thereby actively control tip and sample position to atomic-scale precision in 3D. Here, we demonstrate control of the absolute z-position of the tip, even when it is disengaged from the sample. This provides for independent measurements of tip position and tip force (deduced from the traditional cantilever deflection). This dual z detection could be useful in a broad array of applications that demand precise tip-sample control, including tip-based nanofabrication and single-molecule force spectroscopy.

Spectral effects of AFM tip geometry
Paper 7405-16 of Conference 7405
Date: Tuesday, 04 August 2009
Time: 4:10 PM – 4:30 PM

Author(s): Cornelius F. Hahlweg, Hendrik Rothe, Helmut-Schmidt Univ. (Germany)

Tactile measurement systems like AFM provide a better resolution than optical inspection systems since they are not restricted by the wavelength of light. In turn they introduce distortions, which may lead to harmonics that can even be more powerful than the original spatial oscillations. Since the tip geometry changes because of the dependent tip wear this can lead to complete misinterpretations of the measurement results. We discuss a method to characterize tip geometry effects by a mathematical approach that can also be used in the spectral domain, leading to a spectral description of the resulting signal.
The presented approach is neither based on morphological image processing nor convolution. It can be utilized to determine the obtainable quality of AFM measurements and the limits of surface reconstruction.

Further developments in the implementation of a concept of AFM measurements using a priori knowledge
Paper 7405-17 of Conference 7405
Date: Tuesday, 04 August 2009
Time: 4:30 PM – 4:50 PM

Author(s): Christian Recknagel, Hendrik Rothe, Helmut-Schmidt Univ. (Germany)

The Nanometer-Coordinate-Measuring-Machine is developed for comparatively fast large area scans with high resolution for measuring critical dimensions. The system combines a metrological atomic force microscope with a precise positioning system. The sample is moved under the probe system via the positioning system achieving a scan range of 25 x 25 x 5 mm³ with a resolution of 0.1 nm. A concept for critical dimension measurement using a-priori-knowledge is introduced. The automatic measurement involves intelligent measurement strategies, which are adapted to specific geometries of the measurement feature to reduce measurement time and uncertainty. The practical implementation of this concept focuses on proving the concept.

Atomic Force Microscope AFM HERON - sample quotes
Near-field Scanning Optical Microscope (NSOM) for nano-characterization and nanomanufacturing

Non-linear distortions caused by AFM-tip geometry and limitations of reconstruction on discrete data
Paper 7405-18 of Conference 7405
Date: Tuesday, 04 August 2009
Time: 4:50 PM – 5:10 PM

Author(s): Cornelius F. Hahlweg, Hendrik Rothe, Helmut-Schmidt Univ. (Germany)

In tactile measurement systems like AFM it is obvious that the shape of the tactile tip scanning the surface function determines the measurement result: a certain tip shape will result in a remarkable blurring of edges and also a distortion of smooth surface functions.
These effects are usually treated in a more or less heuristic way by applying morphological operations. In previous papers the highly non-linear nature of the blurring process and the resulting distortions could be shown. Signal processing and reconstruction, the effects of limited spectral band width and the sampling process have to be taken into account. A system approach is presented, modelling the distortions caused by the tactile tip and possible recontruction systems. Guidelines for the desing of the whole signal chain are derived, as well as reconstruction methods and their limitations. The paper discusses system models for analog and digital signal chains and gives some measurement and reconstruction results.

Atomic force microscopy-based nano-characterizations of electrical properties of thin-film solar cell materials and devices
Paper 7409-27 of Conference 7409
Date: Monday, 03 August 2009
Time: 11:15 AM – 11:45 AM

Author(s): Chunsheng Jiang, Helio R. Moutinho, Yanfa Yan, Mowafak M. Al-Jassim, National Renewable Energy Lab. (United States)

Scanning Kelvin probe force microscopy, scanning capacitance microscopy, and conductive-AFM are AFM-based electrical characterization techniques that measure surface potential, carrier concentration, and local conduction path in nanometer resolutions. In this presentation, we will review our recent progress in the characterizations of electrical properties in thin-film solar cell materials and devices, using theses AFM-based techniques. We will present three characterizations of thin-film Si-based materials and devices, each using one of the techniques above, and present grain boundary depletions in CIGS thin films. These characterizations provide useful information for understanding the device physics and improving the material quality and device performances.

Luminescence nanoimaging of quantum and molecular structures using a highly localized plasmon source
Paper 7395-84 of Conference 7395
Date: Thursday, 06 August 2009
Time: 3:45 PM – 4:05 PM

Author(s): Manuel J. Romero, Anthony J. Morfa, Thomas H. Reilly III, Jao van de Lagemaat, National Renewable Energy Lab. (United States)

We have developed an atomic force microscopy (AFM)-based scanning tunneling luminescence microscopy in which tunneling electrons excite plasmon modes confined to the tunneling gap at the tip. This highly localized plasmon source is used for the subsequent excitation of the quantum dot (QD) or molecule being imaged by the AFM tip. Both the SP and the molecular luminescence can be detected optically. We show that the combination of the AFM nanometer resolution and the local spectroscopy of the tunneling luminescence can be used to investigate nanoscale optoelectronics in molecular structures, single-molecule detection and SP-QD coupling.

Single molecule detection using superhydrophobic surfaces and advanced biophotonic devices
Paper 7394-3 of Conference 7394
Date: Sunday, 02 August 2009
Time: 10:00 AM – 10:30 AM

Author(s): Enzo M. Di Fabrizio, Univ. degli studi Magna Græcia di Catanzaro (Italy) and INFM–TASC (Italy)

We report novel micro and nanofabrication techniques for single molecule detection by generating surface plasmons, thus giving a giant electric field. Self-similar Ag-nanosphere based plasmonic devices are fabricated using e-beam and electroless techniques for the characterization of biomolecules.
Another device, comprising tapered nanolens and photonic crystal cavity, has been fabricated on AFM cantilever to perform AFM and Raman measurements, showing great potentials for chemical, structural and morphological study.
Si micropillars would constitute a superhydrobhobic surface which delivers the ability of confining dilute biomolecules into a bounded region of the plane. Major novelty resides in combined use of micro and nano-structures.

Comparison of multilayer laser scribing of thin film solar cells with femto, pico and nanosecond pulse durations
Paper 7409-10 of Conference 7409
Date: Sunday, 02 August 2009
Time: 11:40 AM – 12:00 PM

Author(s): Tai-Wook Kim, Heui-Jae Pahk, Seoul National Univ. (Korea, Republic of); Hee K. Park, AppliFlex LLC (United States); David J. Hwang, Costas P. Grigoropoulos, Univ. of California, Berkeley (United States)

We report experimental studies on laser scribing of thin film solar cells using various types of lasers, to determine the optimum parameters for multilayer structures (P1, P2 and P3) of a-Si and CIGS solar cells. Detailed process parameters such as pulse repetition rate, scanning speed, pulse energy, laser wavelength, and direction of laser illumination relative to substrate are examined. Characteristics are evaluated by AFM and SEM, EDS, and electrical conductance of interconnects by conductive AFM. Issues on defects such as debris, rim formation, thermal damage and inter-diffusion of materials at the interface are discussed on the basis of laser-materials interaction.

Coalescence Overgrowth of GaN Nanocolumns with Patterned Metalorganic Chemical Vapor Deposition
Paper 7406-28 of Conference 7406
Date: Monday, 03 August 2009
Time: 6:00 PM

Author(s): Tsung-Yi Tang, Wen-Yu Shiao, Yung-Sheng Chen, Cheng-Hung Lin, Kun-Ching Shen, Chih-Chung Yang, National Taiwan Univ. (Taiwan); Chiu-Lin Yao, Jui-Hung Yeh, Ta-Cheng Hsu, Epistar Corp. (Taiwan)

High-quality coalescence overgrowth of patterned-grown GaN nanocolumns on c-plane sapphire substrate with metalorganic chemical vapor deposition is demonstrated. From the atomic force microscopy (AFM) measurement, the surface roughness of the overgrown layer is as small as 0.411 nm. Based on the AFM and depth-dependent X-ray diffraction measurements, near the surface of the overgrown layer, the dislocation density is reduced to the order of 10 to 7 per square cm, which is one order of magnitude lower than that of the control sample and 2-3 orders of magnitude lower than those of ordinary GaN templates for fabricating light-emitting diode.

Excitons and multi-excitons in heterostructured semiconductor nanorods
Paper 7393-6 of Conference 7393
Date: Sunday, 02 August 2009
Time: 10:50 AM – 11:20 AM

Author(s): Uri Banin, The Hebrew Univ. of Jerusalem (Israel)

An important frontier in nanocrystal synthesis concerns the growth of heterostructures of different materials in the same nanostructure as means of increasing functionality. An interesting combination is that of two semiconductors where a seeded growth approach can be used to create rod shaped particles with either type I or type II band-alignment. Using different seed dot particles, we describe growth of either types of rod architectures, yielding outstanding emission properties. Such nanoparticles are excellent candidates for biological tagging, optical applications and optical gain media. The use of optical spectroscopy along with STM and STS (scanning tunneling spectroscopy), was implemented to reveal the electronic properties, measure the band-offsets in these systems, and characterize the multi-excitonic spectra and properties. We also use Apertureless near-field scanning optical microscopy (ANSOM), along with time resolving capabilities, to produce high resolution optical imaging and spectroscopy measurements of single nanorods. The strong distance dependent energy transfer between the excited particle and a metallic coated AFM tip provides a contrast mechanism for sub-diffraction limited optical imaging. These optical images are fully synchronized with the AFM scan, which enables us to correlate the optical image with the nanorod topography and resolve the exciton location with sub-20nm resolution.

Ultra-thin films of titanium oxide via UV-assisted decomposition of sol-gel precursors: potential as tandem-cell interlayers and encapsulation layers in organic photovoltaic devices
Paper 7416-68 of Conference 7416
Date: Tuesday, 04 August 2009
Time: 8:00 PM

Author(s): Delvin Tadytin, Diogenes Placencia, Neal R. Armstrong, The Univ. of Arizona (United States)

Titanium oxide sol-gel precursors were used as charge recombination and encapsulation layers in titanyl phthalocyanine (TiOPc)/C60-based organic photovoltaics. A chemical vapor deposition (CVD) chamber was constructed to deposit the titanium oxide thin films under rough vacuum conditions. Stoichiometric and sub-stoichiometric oxides were generated and x-ray photoelectron spectroscopy (XPS) along with conductive-tip atomic force microscopy (C-AFM) and field-emission scanning electron microscopy (FE-SEM) were used to characterize the films.

Single wall nanotubes forests as demonstration for nanotubes length controlling
Paper 7399-30 of Conference 7399
Date: Wednesday, 05 August 2009
Time: 5:30 PM

Author(s): Francesco Lamberti, Moreno Meneghetti, Nicola Elvassore, Univ. degli Studi di Padova (Italy)

we propose a novel method to control single wall nanotubes (SWNTs) length following a solfonitric oxidation/etching step monitoring not the time, as others have just monstrated, but the temperature of the ultrasonic bath during the shortening step. This procedure could be simply demonstrated as the best for obtaining a good reproducibility.
Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) revealed that the tubes treated at different temperatures have dissimilar defects concentrations along the tubes while atomic force microscopy (AFM) on self-assembled monolayers of SWNTs (forests) confirmed finally that to different bath temperatures correspond different nanotubes' heights.

Effect of Pr2O3 doping on the structural and optical properties of RF magnetron sputtered ZnO thin films
Paper 7404-27 of Conference 7404
Date: Thursday, 06 August 2009
Time: 12:00 PM – 12:20 PM

Author(s): R. Vinodkumar, I. Navas, Detty P. Alappatt, Renju R. Krishnan, Vellara P. Mahadevan Pillai, Univ. of Kerala (India)

In order to study the effect of praseodymium oxide doping, ZnO and Pr2O3 doped (1, 3 and 5 wt %) ZnO films are prepared by RF Magnetron Sputtering and are characterized by techniques like XRD, SEM, EDX, AFM, UV-Visible spectroscopy and Photoluminescence spectroscopy.


Atomic Force Microscope AFM HERON - sample quotes
Near-field Scanning Optical Microscope (NSOM) for nano-characterization and nanomanufacturing

Plasma enhanced chemical vapour deposition assisted growth of graphene films
Paper 7399-29 of Conference 7399
Date: Thursday, 06 August 2009
Time: 5:10 PM – 5:30 PM

Author(s): Laurent Baraton, Ecole Polytechnique (France); Laurent Gangloff, Stéphane Xavier, Thales Research & Technology (France); Costel S. Cojocaru, Ecole Polytechnique (France); Pierre Legagneux, Thales Research & Technology (France); Vincent Huc, Univ. Paris-Sud 11 (France); Young-Hee Lee, Sungkyunkwan Univ. (Korea, Republic of); Didier Pribat, Ecole Polytechnique (France)

Graphene, a one atom thick carbon layer, is the emerging material in the field of nanoscience and nanotechnology. Its amazing properties allow researchers to consider an unprecedented wide range of applications, but such developments require a reliable, low cost and easily scalable synthesis process of graphene films.
In this communication we expose a growth process based on low temperature plasma enhanced chemical vapour deposition techniques. The films grown using this method were characterised using classical methods (Raman spectroscopy, AFM, SEM) and films conductivity is found to be close to those reported by others.

Third-order nonlinear optical characteristics and the morphologies of polythiophene derivative thin films fabricated by solution method
Paper 7413-2 of Conference 7413
Date: Sunday, 02 August 2009
Time: 8:50 AM – 9:05 AM

Author(s): Shizuyasu Ochiai, Suguru Mototani, Kenzo Kojima, Teruyoshi Mizutani, Aichi Institute of Technology (Japan)

The PATs thin film were prepared dropping liquid droplets on a quartz glass surface treated with hexamethyldisilazane (HMDS). The molecular orientation or alignment of P3AT thin films with and without HMDS was observed by using an X-ray Diffraction (XRD) spectrometer, UV/Vis spectrophotometer and Atomic Force Microscorp(AFM) and nonlinear-optical-characteristics were performed by Maker-fringe method. The results indicate that P3OT thin film with HMDS has an excellent nonlinear-optical property. In the P3OT thin film, the orientation is parallel to the surface. The shape of the grain forms nano-fiber. These findings indicate that the P3OT-thin film has an excellent nonlinear-optical property.

Electric field modulated directional energy flow in strongly-coupled quantum dot nano-assemblies
Paper 7393-9 of Conference 7393
Date: Sunday, 02 August 2009
Time: 12:00 PM – 12:20 PM

Author(s): Yashwant K. Verma, Somnath Ghosh, Maribel Gallardo, Christopher G. Ferri, Sayantani Ghosh, Univ. of California, Merced (United States)

We report about our technique of creating macroscopically ordered aggregates of strongly-coupled disk-shaped colloidal QDs by suspending them in a matrix of nematic liquid-crystal molecules (NLC) at room-temperatures. High resolution ultrafast optical spectroscopy reveals the strength of the interdot coupling to be far greater than previously observed in other colloidal QDs. AFM images have demonstrated that aggregation occurs by stacking of the disk-shaped QDs, while DLS measurements on isolated and QD-NLC matrix reveal the aggregates to be composed of tens of QDs. Liquid-crystal molecules allow us to reversibly alter the spatial orientation of the coupled QDS in situ by application of electric fields. The electrical modulation, which controllably alters the directionality of energy flow along preferred axes, is an important functionality for applications in opto-electronic devices.
This work was supported by ARO.

3D measurement method based on wavelet transform by using SEM
Paper 7432-6 of Conference 7432
Date: Monday, 03 August 2009
Time: 9:40 AM – 10:00 AM

Author(s): Yasuhiko Arai, Kansai Univ. (Japan)

A novel three-dimensional measurement method for micro size products is proposed by using Wavelet transform and the electron-beam of SEM. Fringe image as the shadow of grating is analyzed. A bearing ball whose diameter is 500 micro-meter was measured by this system using the grating of which pitch is 12 micro-meter. The accuracy of the proposed method is discussed using this result. A three dimensional micro-construction of the head of a hard disk is measured by the system using the grating of which pitch is 4 micro-meter. From comparison with AFM, it is confirmed that the proposed method has high-resolution power.

Comparative study of X-Ray scattering by first-order perturbation theory and generalized Harvey-Shack theory
Paper 7448-35 of Conference 7448
Date: Monday, 03 August 2009
Time: 6:00 PM

Author(s): Yonggang Wang, Changchun Institute of Optics, Fine Mechanics and Physics (China)

Applications of the x-ray scattering (XRS) technique for studying super-smooth are discussed. The XRS method is demonstrated to enable quantitative evaluation of PSD functions and effective roughness of super-smooth surfaces. Within the calculation of PSD function and effective roughness, comparative study between first-order perturbation theory and generalized Harvey-shack theory are performed. The calculated values all are in a good agreement with the results obtained from Atomic force microscope (AFM), especially the generalized Harvey-shack theory because of no explicit smooth surface approximation. Both of the theories also can allow accurate predictions of image degradation due to scattering effects in X-ray telescopes. The experimental schemes are analyzed and systematic errors on the determination of PSD functions are evaluated.

Novel approaches to biosensing and nano-biological interactions
Paper 7397-6 of Conference 7397
Date: Tuesday, 04 August 2009
Time: 10:40 AM – 11:10 AM

Author(s): Nathaniel C. Cady, Univ. at Albany (United States)

Nanotechnology has recently been applied to a wide range of biological systems. In particular, there is a current push to examine the interface between the biological world and micro/nano-scale systems. My research in this field has led to the development of novel strategies for spatial patterning of biomolecules, electrical and optical biosensing, nanomaterial delivery systems, single-cell manipulation, and the study of cellular interactions with nano-structured surfaces. Current work on these topics will be presented, including work on novel, semiconductor-based DNA detection methods and mechanical, atomic force microscopy (AFM)-based characterization of bacterial biofilms in three-dimensional microfluidic systems.

Surface characterization of CdZnTe crystals for fabricating radiation detectors
Paper 7449-23 of Conference 7449
Date: Tuesday, 04 August 2009
Time: 11:10 AM – 11:30 AM

Author(s): Anwar M. Hossain, Brookhaven National Lab. (United States); Oluseyi S. Babalola, Fisk Univ. (United States); Aleksey E. Bolotnikov, Giuseppe S. Camarda, Yonggang Cui, Ge Yang, Ki Hyun Kim, Ralph B. James, Brookhaven National Lab. (United States)

Surface processing is an important step in detector manufacturing process. Surface properties control many aspects of device's performance. We studied the topographic features of the various processed surfaces of CdZnTe crytals. We prepared the crystals' surfaces in two ways: 1) By mechanical polishing to various extents, from 5 m to the lowest 0.05 m, and then chemically etching them with Bromine-Methanol solution; and, 2) By chemo-mechanical polishing. Thereafter, we used Atomic Force Microscopy (AFM) to reveal the features of the surfaces of both. We measured the electrical properties of the fabricated devices, correlating our findings with the corresponding surface features to optimize processing treatments, so yielding the best surfaces for manufacturing high-quality CdZnTe radiation-detectors.

Fabrication of nanoimprinting molds by two-photon polymerization
Paper 7405-14 of Conference 7405
Date: Tuesday, 04 August 2009
Time: 3:00 PM – 3:20 PM

Author(s): Wande Zhang, Li-Hsin Han, Shaochen Chen, The Univ. of Texas at Austin (United States)

Fabricating nanoimprinting molds usually involves numerous costly and time-consuming steps. We demonstrate the plausibility of making low-cost nanoimprinting molds easily by using the femtosecond-laser-induced two-photon polymerization (TPP) technique. Importantly, using TPP to make nanoimprinting modes also enables the utilization of TPP’s capacity to make fine nanoscale structures in mass production. A Ti:sapphire femtosecond laser was used to induce TPP to make 400-nm-width lines on glass substrate, our nanoimprinting mold. Poly (ethylene glycol) diacrylate was then patterned by the mold to demonstrate its imprinting capacity. The results were analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM).

High electron mobility and ambient stability in solution-processed perylene-based organic field effect transistors
Paper 7417-46 of Conference 7417
Date: Tuesday, 04 August 2009
Time: 5:15 PM – 5:30 PM

Author(s): Claudia Piliego, Lawrence Berkeley National Lab. (United States) and Zernike Institute for Advanced Materials (Netherlands); Dorota Jarzab, Univ. of Groningen (Netherlands); Zhihua Chen, Antonio F. Facchetti, Polyera Corp. (United States); Maria A. Loi, Univ. of Groningen (Netherlands)

We report the realization of bottom-contact bottom-gate OFETs based on spin-coated films of N,N’-1H,1H-perfluorobutyl dicyanoperylenediimide (PDI-FCN2) which combines high solubility, elevated electron mobility, and good air stability. The devices fabricated by employing a simple and inexpensive solution-deposition technique, exhibit a saturation regime mobility of 0.15 cm2/Vs (0.08 cm2/Vs in ambient), a threshold voltage of -5.6V and an IOn/IOff ratio greater than 1000. These performances, which are the highest ever reported for a bottom contact configuration, have been correlated to the morphological and optical characteristic of the film by performing atomic force microscopy (AFM) and confocal laser microscopy (CLM)investigations.

Solvent effect on the morphology of P3HT/PCBM films
Paper 7416-63 of Conference 7416
Date: Tuesday, 04 August 2009
Time: 8:00 PM

Author(s): Yu Xie, Pavel Dutta, Dorin Cengher, Venkat Bommisetty, Jing Li, David W. Galipeau, Qiquan Qiao, South Dakota State Univ. (United States)

This work reports the study of solvent effects on morphology for P3HT/PCBM films using chlorobenzene, 1, 2-dichlorobenzene and 1, 3-dichlorobenzene. Atomic force microscopy (AFM), scanning electron microscopy (SEM) and UV-Vis absorption spectra were performed to study the film morphology using chlorobenzene, 1, 2-dichlorobenzene and 1, 3-dichlorobenzene as solvent. Initial studies showed that there were fewer nanoclusters (~200 nm diameter) in 1, 3-dichlorobenzene based films than in chlorobenzene based films. In addition, an obvious red shift was observed in the UV-Vis absorption spectra for the P3HT/PCBM blend from 1, 3-dichlorobenzene compared to that from chlorobenzene. Work is under way to compare the electron transport pathway toward the electrode using Kelvin Probe Force Microscopy of the films spin coated from solutions of chlorobenzene, 1, 2-dichlorobenzene and 1, 3-dichlorobenzene, respectively.


Optical and structural properties of In1-xGaxN layers grown by HPCVD
Paper 7422-23 of Conference 7422
Date: Wednesday, 05 August 2009
Time: 8:45 AM – 9:05 AM

Author(s): Max Buegler, Göksel Durkaya, Georgia State Univ. (United States); Enno Malguth, Georgia State Univ. (United States) and Technische Univ. Berlin (Germany); William E. Fenwick, Ian T. Ferguson, Georgia Institute of Technology (United States); Nikolaus Dietz, Georgia State Univ. (United States)

The In1-xGaxN alloy system has potential for high efficiency solar energy conversion and advanced optoelectronic applications. Ga1-xInxN/In1-xGaxN hetero-structures can be engineered to be responsive from UV to IR wavelength regime. This contribution focuses on the structural and optical characterization of In1-xGaxN layers and heterostructures grown by ‘high-pressure chemical vapor deposition (HPCVD), a growth technique enabling elevated temperatures using 15 to 20 bar nitrogen overpressure in order to suppress thermal disassociation of In1-xGaxN layers.
We will present structural and optical analysis of In1-xGaxN layers studied by Raman spectroscopy (RS), X-Ray Diffraction (XRD), Optical Transmission Spectroscopy (OTS) and atomic force microscopy (AFM).

An experimental investigation of Fang's Ag superlens suitable for integration
Paper 7395-57 of Conference 7395
Date: Wednesday, 05 August 2009
Time: 11:20 AM – 11:40 AM

Author(s): Claus Jeppesen, Rasmus B. Nielsen, Sanshui Xiao, Niels A. Mortensen, Technical Univ. of Denmark (Denmark); Alexandra E. Boltasseva, Purdue Univ. (United States); Anders Kristensen, Technical Univ. of Denmark (Denmark)

We report on experimental realization of the Fang Ag superlens structure replacing PMMA with a highly chemical resistant copolymer, mr-I T85. Mr-I T85 is compatible with further processing involving acids and polar solvents. Our superlens stack consisted of a quartz/chrome grating mask, 40 nm of mr-I T85, 35 nm Ag, and finally 100 nm mr-6000UVL. The exposures took place in a UV-aligner at 365 nm and supporting COMSOL simulations were made to illustrate the field distribution. AFM scans of the exposed structure revealed 120-140 nm gratings. The superlens is to be embedded in a bioplatform.

Massively parallel fabrication and characterization of DNA templated magnetic wires
Paper 7397-34 of Conference 7397
Date: Wednesday, 05 August 2009
Time: 5:00 PM – 5:30 PM

Author(s): Albena Ivanisevic, Purdue Univ. (United States)

A long DNA molecule was used to guide the assembly of pyrrolidinone capped Fe2O3 and CoFe2O3 particles, as well as poly-lysine coated gold nanoparticles. The resulting DNA templated wires were stretched onto silicon oxide surfaces using a receding meniscus procedure. The coated, stretched and surface bound wires were characterized using atomic force microscopy (AFM), magnetic force microscopy (MFM), and spectroscopic methods. The results with respect to the wire properties were correlated with those determined from the bulk properties of the nanoparticles and with the properties of the bulk DNA. The MFM measurements allowed us to visualize the formation of domains along the wires, as well as qualitatively compare the magnetic properties of each templated structure. This report will also describe how templated DNA can be used as a dynamic material scaffold capable of being enzymatically reduced to smaller fragments, and subsequently re – joined to become a long strand.

Nanoimprint lithography for complex 3D micro-nano structures replication under low temperature
Paper 7402-29 of Conference 7402
Date: Wednesday, 05 August 2009
Time: 5:30 PM

Author(s): Hongwen Sun, Hohai Univ. (China); Jingquan Liu, Di Chen, Shanghai Jiao Tong Univ. (China)

Focused Ion Beam (FIB) was imployed to fabricate nanoimprint stamps. Complex 3D micro-nano patterns were fabricated including the emblems of Beijing 2008 Olympic Games and Shanghai 2010 World Expo on a single stamp. These micro/nano structures were then faithfully replicated to SU-8 2000.1 resist, with low imprint temperature. Field emission-scanning electron microscope (FE-SEM) and atomic force microscopy (AFM) were used to characterize both stamp and replica’s surface profile and replication fidelity. The results show that NIL with the FIB fabricated stamps can successfully replicate complex 3D micro-nano SU-8 structures at the same time under low temperature.

Sensoric applications based on plasmonic effects at metal nanoparticles
Paper 7395-69 of Conference 7395
Date: Thursday, 06 August 2009
Time: 8:00 AM – 8:25 AM

Author(s): Andrea Csaki, Marie Loechner, Thomas Schneider, Andrea Steinbrück, Wolfgang Fritzsche, IPHT Jena (Germany)

Metal nanoparticles exhibit a large potential for sensoric applications due to localized surface plasmon resonance (LSPR). LSPR bands are sensitive to the material or the immediate environment of the particles.
We followed the optical properties of nanoparticles at a single molecule level in-situ during wet chemical reactions. On the other hand, correlative microscopy combining AFM measurements of a particle with its spectrum allow for the characterization of structure-property relations. Preliminary findings point to Au/Ag core/shell particles of certain dimensions as especially sensitive to spectral changes upon analyte binding as compared to pure metal particles.

Infrared antennas for near-field microscopy and enhanced near-field spectroscopy
Paper 7395-71 of Conference 7395
Date: Thursday, 06 August 2009
Time: 8:50 AM – 9:15 AM

Author(s): Thomas Taubner, RWTH Aachen (Germany); Jon A. Schuller, Mark L. Brongersma, Stanford Univ. (United States)

I will present new concepts for increasing the sensitivity of infrared scattering-type near-field optical microscopy (s-SNOM). S-SNOM relies on the scattering of light at a sharp metallic tip to obtain images with subwavelength resolution. The use of mid-infrared light allows to acquire spectroscopic information on a sample’s chemical, structural and electronic properties.

One way to increase sensitivity is to create plasmon resonant nanostructures from metal-coated AFM tips. Thus they can act as “optical antennas” by concentrating light into tiny, subwavelength volumes. The second strategy is to enhance the near-field probing process of thin molecular layers by suitable substrates.

Nanoscale resolved infrared spectra of a thermal oxide using s-SNOM and QC lasers
Paper 7395-86 of Conference 7395
Date: Thursday, 06 August 2009
Time: 4:25 PM – 4:45 PM

Author(s): Greg O. Andreev, Gerardo Dominguez, Mark Thiemens, Fritz Keilmann, Dmitri N. Basov, Univ. of California, San Diego (United States)

We present ~20nm resolution IR images of a thermal oxide (SiO2) on Si for wavelengths ranging from λ=7.96um to 8.47um. The images are taken with an s-SNOM built around a commercial AFM (Attocube). The light source is a Quantum Cascade Laser (Daylight Solutions) with continuous tuning. The tunability of the QCL allowed us to acquire IR spectra of a (<100nm)2 area in <100s. The spectra show clear differences between SiO2, Si, and particulates on the sample. These proof of concept results show that rapidly tunable QC lasers combined with s-SNOM offer a feasible means for nanoscale material discrimination.


Nanoptical characterization of plasmonic nanostructures and devices with single and multiprobe NSOM (Keynote Presentation) (Keynote Presentation)
Paper 7394-1 of Conference 7394
Date: Sunday, 02 August 2009
Time: 8:30 AM – 9:15 AM

Author(s): Aaron Lewis, The Hebrew Univ. of Jerusalem (Israel)

More than two decades ago our group investigated plane wave light transmission and the transmission of fluorescence through nano aperture arrays in gold palladium films [1-2]. In our earliest report [1] we reported that “Although the transmission through 1 m apertures appears consistent with exact electromagnetic field calculations there appears to be more transmission through the smallest apertures than theoretical prediction.” About a decade and a half after our investigations Ebbesen and coworkers verified our observations and explained the large transmission property of such nano-hole arrays as an effect involving surface plasmons (SPs) [3,4]. Since Ebbesen’s paper in 1998, nano-holes arrays have generated both theoretical and experimental interest in order to understand the physics involved in the Extraordinary Optical Transmission (EOT) through such arrays [5-8]. The experimental investigations undertaken have generally focused on far-field optics. Nonetheless, the optical near-field plays a major role in the enhancement process and so is integral to developing a full understanding. This paper will summarize these near-field optical investigations completed by our group and others. Such investigations have resulted in new understandings of the distribution of plasmon propagation in these nano-arrays. We will also demonstrate controlled perturbation of such surface plasmon propagation in these nano arrays by employing on-line an apertured near-field optical probe in concert with a single gold ball AFM probe.

Atomic Force Microscope AFM HERON - sample quotes
Near-field Scanning Optical Microscope (NSOM) for nano-characterization and nanomanufacturing