| Local Vibrational Modes of Carbon-Hydrogen Complexes in Proton Irradiated AlGaN |
JAN 2002 |
7 pages |
| Authors:
M. O. Manasreh; B. D. Weaver; NEW MEXICO UNIV ALBUQUERQUE DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
|
 | Local vibrational modes (LVMs) of carbon-hydrogen (C-H) complexes in proton implanted AlGaN grown on sapphire by metalorganic chemical vapor deposition (MOCVD) were investigated using Fourier transform infrared (FTIR) spectroscopy. The LVMs exhibit five distinctive peaks in the spectral region of 2846 ^ 2963/cm, which are due to the symmetric and asymmetric stretching modes of C-H(sub n) (n=1-3). The LVMs intensities in doped AlGaN are increased as irradiation dose is increased ... |
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| Effects of Ion Bombarding and Nitrogenation on the Properties of Photovoltaic a-CNx Thin Films |
JAN 2002 |
6 pages |
| Authors:
Z. B. Zhou; R. Q. Cui; G. M. Hadi; Q. J. Pang; C. Y. Jin; SHANGHAI JIAO TONG UNIV (CHINA)
|
| Amorphous carbon nitride films (a-CN(x)) were synthesized by using single ion beam sputtering of a graphite target in argon and nitrogen sputtering gases. This thin film could be used as a novel photovoltaic material. The films were characterized with the technique of laser Raman, spectroscopic ellipsometry and electron spin resonance spectrometer (ESR). In this paper we report the effects of ion impacting and nitrogenation on the microstructure, density of defect ... |
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| Effects of Electric Fields on Cathodoluminescence from II-VI Quantum Well Light Emitting Diodes |
JAN 2002 |
6 pages |
| Authors:
A. Y. Nikiforov; G. S. Cargill III; M. C. Tamargo; S. P. Guo; Y. C. Chen; LEHIGH UNIV BETHLEHEM PA DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| Effects of electrical bias on the cathodoluminescence (CL) have been investigated for a blue II-VI quantum well (QW) light emitting diode structure of ZnCdMgSe, lattice-matched to InP. In CL wavelength scans, the observed effects include largely reversible changes in QW CL intensity and wavelength and changes in cladding CL intensity. In CL time-based scans, the QW CL intensity showed both immediate and long term changes with bias. Irreversible, degradation-related decreases ... |
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| Effect of Zn Atom Diffusion in the Active Layer of InGaAlP Visible-LED Investigated by the Piezoelectric Photothermal Spectroscopy |
JAN 2002 |
6 pages |
| Authors:
Ryuji Ohno; Yoshihito Taiji; Shoichro Sato; Tetsuo Ikari; Atsuhiko Fukuyama; MIYAZAKI UNIV (JAPAN) DEPT OF ELECTRICAL AND ELECTRONIC ENGINEERING
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| It has been reported that Zn atoms diffused from the Zn-doped p-InAlP cladding to the active layer in InGaAlP visible-light-emitting diodes cause a degradation of light output efficiency. A doping effect of the Zn atoms was then investigated using a Piezoelectric Photothermal Spectroscopy from a nonradiative transition point of view. The results indicate that the Zn-doping unexpectedly induces a decrease of the nonradiative component of the electron transitions above the ... |
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| Improved Routes Towards Solution Deposition of Indium Sulfide Thin Films for Photovoltaic Applications: |
JAN 2002 |
6 pages |
| Authors:
Kuveshni Govender; David Smyth-Boyle; Paul O'Brien; MANCHESTER UNIV (UNITED KINGDOM)
|
| Conditions necessary for the reproducible deposition of pristine In2S3 thin films on TO-glass substrates by low temperature solution deposition have been identified. Baths containing carboxylic acids yield adherent, specular and crystalline films, within a defined pH range, dependent on the particular acid employed. Films have been characterised by XRD, SEM, XPS and electronic spectroscopy. As-deposited films were found to crystallise as tetragonal Beta-In2S3, no evidence for incorporation of hydroxy-indium species ... |
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| Thermal Anneal Effects on Carbon-Hydrogen LVMs in A1GaN |
JAN 2002 |
6 pages |
| Authors:
M. O. Manasreh; B. D. Weaver; NEW MEXICO UNIV ALBUQUERQUE DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
|
| Thermal annealing effects on carbon-hydrogen (C-H) complexes defects in AlGaN grown on sapphire by metalorganic chemical vapor deposition (MOCVD) technique have been investigated using Fourier transform infrared spectroscopy (FTIR). The CH complexes in AlGaN, formed either during growth or by proton irradiation, exhibit five local vibrational modes (LVMs) due to the symmetric and asymmetric vibrational stretching modes of C-H in CH(sub n) (n = 1-3) defect complexes. It was found ... |
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| Optical Vibrational and Structural Properties of Ge1-xSnx Alloys by UHV-CVD |
JAN 2002 |
6 pages |
| Authors:
Jennifer Taraci; S. Zollner; M. R. McCartney; Jose Menendez; D. J. Smith; ARIZONA STATE UNIV TEMPE DEPT OF CHEMISTRY
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| UHV-CVD growth based on a deuterium stabilized Sn hydride and digermane produces Ge-Sn alloys with tunable bandgaps. The Ge(1-x)Sn(x) (x=2-20 at.%) alloys are deposited on Si (100) and exhibit superior crystallinity and thermal stability compared with MBE grown films. Composition, crystal and electronic structure, and optical and vibrational properties are characterized by RBS, low energy SIMS, high resolution electron microscopy TEM, x-ray diffraction, as well as Raman and IR spectroscopies. ... |
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| Pulsed Laser Deposition and Characterization of Zn(1-x)Mn(x)O Films |
JAN 2002 |
6 pages |
| Authors:
C. Jin; A. Tiwari; A. Kvit; D. Kumar; J. Muth; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| Here we present our results of structural, optical, and magnetic measurements of Zn(1-x)Mn(x)O thin films. These films were grown epitaxially on (0001) sapphire substrates by using pulsed laser deposition technique. The maximum Mn content (x = 0.36) is found to be much higher than allowed by thermal equilibrium limit (x-0.13) due to the non-equilibrium nature of the pulsed laser deposition. All the films investigated here were found to be single ... |
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| Growth of the Single-Crystalline ZnO Films on Si (111) Substrates by Plasma-Assisted Molecular-Beam Epitaxy |
JAN 2002 |
6 pages |
| Authors:
Kazuto Koike; Takanori Tanite; Shigehiko Sasa; Masataka Inoue; Mitsuaki Yano; OSAKA INST OF TECHNOLOGY (JAPAN)
|
| This report describes the growth of single-crystalline ZnO films on Si (111) substrates by plasma-assisted molecular-beam epitaxy. X-ray diffraction measurement shows that c-axis oriented ZnO films are easily grown on Si (111) substrates. However, in-plane random rotational domains are included in the ZnO films due to the inevitable oxidation of substrate surface at the initial stage of ZnO growth. By employing a thin CaF2 buffer layer between the ZnO films ... |
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| Optical Study of 2D Photonic Crystals in an InP/GaInAsP Slab Waveguide Structure |
JAN 2002 |
6 pages |
| Authors:
Rolando Ferrini; David Leuenberger; Mikael Mulot; Min Qiu; Jurgen Moosburger; WUERZBURG UNIV (GERMANY F R)
|
| We report on the optical properties of two dimensional (2D) photonic crystals (PCs) deeply etched in an InP/GaInAsP step-index waveguide. Transmission (T) measurements through simple PC slabs and through one-dimensional (1D) Fabry-Perot (FP)) cavities between PC mirrors are reported and compared to theory. A 2D finite difference time-domain (FDTD) method combined to a phenomenological out-of-plane loss model is used to assess different loss contributions. The PC optical properties are deduced ... |
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| Fabrication of Microstructures for Microphotonic Circuit |
JAN 2002 |
5 pages |
| Authors:
Subhasish Chakraborty; D. G. Hasko; R. J. Mears; CAMBRIDGE UNIV (UNITED KINGDOM) DEPT OF ENGINEERING
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| We describe fabrication of sub-micron photonic bandgap structures on Si/SiO2 optical waveguide, which could be used at lambda = 1.54 micrometers. |
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| Artificial Second Order Non-Linearity in Photonic Crystals |
JAN 2002 |
5 pages |
| Authors:
A. Feigel; Z. Kotler; B. Sfez; ISRAEL ATOMIC ENERGY COMMISSION YAVNE SOREQ NUCLEAR RESEARCH CENTRE
|
| We describe a technique for obtaining effective second order non-linearity X(sup 2) in non-centro-symmetric Photonic Crystal made from centro-symmetric materials (e.g., glass, Ge or Si). The effect is based on the electric quadrupole transition, strong electromagnetic mode deformation and different contributions to the volume polarization from different parts of the photonic crystal. |
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| Transmission Characterization of Drilled Alternating-Layer Three-Dimensional Photonic Crystals |
JAN 2002 |
6 pages |
| Authors:
Eiichi Kuramochi; Masaya Notomi; Itaru Yokohama; Jun-ichi Takahashi; Chiharu Takahashi; TOHOKU UNIV SENDAI (JAPAN)
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| We propose a new three-dimensional photonic crystal structure or drilled alternating-layer photonic crystal (DALPC), which can be fabricated by a combination of the deposition of alternating layers of dielectric films and one-time dry etching. Our band calculation predicts that the DALPC has a photonic band gap (PBG) in all directions. We fabricated a Si/SiO2 DALPC by electron beam lithography. bias sputtering, and fluoride-gas electron cyclotron resonance etching. We measured the ... |
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| Space Radiation Effects in Advanced Solar Cell Materials and Devices |
JAN 2002 |
12 pages |
| Authors:
R. J. Walters; G. P. Summers; NAVAL RESEARCH LAB WASHINGTON DC
|
| An investigation of the physical mechanisms governing the response of III-V based solar cells to particle irradiation is presented. The effect of particle irradiation on single and multijunction solar cells is studied through current vs. voltage, spectral response, and deep level transient spectroscopy measurements. The basic radiation response mechanisms are identified, and their effects on the solar cell electrical performance are described. In particular, a detailed analysis of multijunction In(x)Ga(1-x)P/In(y)Ga(1-y)As/Ge ... |
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| Preparation of CdS/ZnO Core/shell Structured Nanoparticies by Hydrothermal Method |
JAN 2002 |
5 pages |
| Authors:
Chunhua Yan; Lingdong Sun; Xuefeng Fu; Chunsheng Liao; PEKING UNIV BEIJING (CHINA)
|
| CdS and ZnO capped CdS (CdS/ZnO) semiconductor nanoparticles were synthesized via hydrothermal method by thermal decomposition of the cysteine-cadmium and Zn(OH)4(2-) complex precursors. Both of the photoluminescence properties and structure characterization confirmed the core/shell structure as expected. Compared to CdS nanoparticles, the band-gap emission of CdS/ZnO was greatly improved, that means the capping layer of ZnO modified the surface of CdS and reduced the surface defects effectively. ED and XRD ... |
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| Optical Characterization of IV-VI Mid-Infrared VCSEL |
JAN 2002 |
7 pages |
| Authors:
F. Zhao; H. WU; T. Zheng; P. J. McCann; A. Majumdar; OKLAHOMA UNIV NORMAN SCHOOL OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
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| PbSe/PbSrSe multiple-quantum-well (MQW) structures and PbSrSe thin films were grown on BaF2 (111) substrates by molecular beam epitaxy (MBE) and characterized by Fourier transform inflated (FTIR) spectrometer. Strong photoluminescence without Fabry-Perot interference fringes was observed even at room temperature from the MQW structures. The peak energies for the MQW structures with different well widths shifted to high energy with increasing temperature. The absorption edge of PbSrSe layer was determined by ... |
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| Progress in Semiconductor Materials for Optoelectronic Applications Symposium held in Boston, Massachusetts on November 26-29, 2001. |
JAN 2002 |
|
| Authors:
Eric D. Jones; Omar Manasreh; Kent D. Choquette; Daniel J. Friedman; Daniel K. Johnstone; MATERIALS RESEARCH SOCIETY WARRENDALE PA
|
 | InGaAsP/InP multiple quantum wells have been prepared by Impurity- Free Vacancy Disordering (IFVD). The luminescent characteristics was investigated using photoluminescence (PL) and photoreflectance (PR), from which the band gap blue shift was observed. SiN4, SiO2 and SOG were used for the dielectric layer to create the vacancies. All samples were annealed by rapid thermal annealing (RTA). The results indicate that the band gap blue shift varies with the dielectric layers ... |
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| Calculations of Dielectric Constant for AlGaInAs Quaternary Semiconductor Alloy in the Transparent Region and Above (O.4-4.OeV) |
JAN 2002 |
6 pages |
| Authors:
M. Linnik; A. CHRISTOU; MARYLAND UNIV COLLEGE PARK
|
| The modeling of the spectral behavior of the refractive index of AlGaInAs quaternary III-V semiconductor alloy in the energy range from 0.4 to 4 eV, including the transparent region, is presented. The extended model of interband transition contributions incorporates not only the fundamental absorption edge contribution to the dielectric function, but also contributions from higher energy and indirect transitions. It is demonstrated that indirect energy transitions must be included in ... |
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| Characterization of LiInS2 and LiInSe2 Single Crystals for Nonlinear Optical Applications |
JAN 2002 |
6 pages |
| Authors:
Ludmila Isaenko; Alexander Yelisseyev; Sergei Lobanov; Alexander Panich; Vitaly Vedenyapin; BEN-GURION UNIV OF THE NEGEV BEERSHEBA (ISRAEL) DEPT OF PHYSICS
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| X-ray structural analysis, nuclear magnetic resonance, optical spectroscopy and second harmonic generation were used to characterize the new nonlinear crystals LiINS2 and LiInSe2 which possess maximum band gap (3.59 and 2.86 eV at 300 K, respectively) among ternary chalcogenides. As grown crystals are only slightly colored while color change after annealing is due to native point defects. |
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| Successes and Predictions of a Pseudopotential Approach in Anion-Mixed Nitrides |
JAN 2002 |
12 pages |
| Authors:
L. Bellaiche; A. Al-Yacoub; N. A. Modine; E. D. Jones; ARKANSAS UNIV FAYETTEVILLE DEPT OF PHYSICS
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| The construction and the parameters of a new-strain dependent empirical pseudopotentials method are described and provided, respectively. This method is shown to reproduce with a very high accuracy some observed unusual properties in various complex anion-mixed nitride alloys. This method is also used to predict and understand anomalous effects that remain to be experimentally discovered in Ga(1-y)In(y)As(1-x)N(x) quaternaries and GaA(0.5-x)P(0.5-x)N(2x) solid solutions. |
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| The Role of Nitrogen-Induced Localization and Defects in InGaAsN (2% N): Comparison of InGaAsN Grown by Molecular Beam Epitaxy and Metal-Organic Chemical Vapor Deposition |
JAN 2002 |
8 pages |
| Authors:
Steven R. Kurtz; A. A. Allerman; J. F. Klem; R. M. Sieg; C. H. Seager; SANDIA NATIONAL LABS ALBUQUERQUE NM
|
| Nitrogen vibrational mode spectra, Hall mobilities, and minority carrier diffusion lengths are examined for InGaAsN (approx. 1.1 eV bandgap) grown by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD). Independent of growth technique, annealing promotes the formation of In-N bonding, and lateral carrier transport is limited by large scale (>> mean free path) material inhomogeneities. Comparing solar cell quantum efficiencies for devices grown by MBE and MOCVD, we ... |
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| Growth of High Nitrogen Content GaAsN by Metalorganic Chemical Vapor Deposition |
JAN 2002 |
6 pages |
| Authors:
J. C. Roberts; B. F. Moody; P. Barletta; M. B. Aumer; S. F. LeBoeuf; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| The incorporation of a high percentage of nitrogen in the GaAs lattice has been the subject of recent interest to reduce the bandgap while maintaining the nearly lattice matched condition to GaAs. We will report on the metalorganic chemical vapor deposition (MOCVD) of GaAsN using trimethylgallium (TMG), tertiarybutylarsine (TBA) and dimethylhydrazine (DMHy) organometallic sources in a hydrogen-free carrier gas. A nitrogen concentration as high as 8% in GaAsN was achieved. ... |
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| Raman and Photoluminescence Mapping of Lattice Matched InGaP/GaAs Heterostructures |
JAN 2002 |
6 pages |
| Authors:
G. Attolini; P. Fallini; F. Germini; C. Pelosi; O. Martinez; VALLADOLID UNIV (SPAIN) SISICA DE LA MATERIA CONVENSADA
|
| The influence of the substrate on composition and CuPt-type spontaneous order of MOVPE lattice matched InGaP/GaAs layers was studied. The study was carried out by microRaman and microphotoluminescence. The order was determined by the band gap, while the Raman parameters were also contributed by the surface topography that was also related to the type of substrate. The spontaneous order increases with Si-doping of the substrates. Doping the layers with Zn ... |
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| Luminescent Characteristics of InGaAsP/InP Multiple Quantum Well Structures by Impurity-Free Vacancy Disordering |
JAN 2002 |
6 pages |
| Authors:
J. Zhao; X. D. Zhang; Z. C. Feng; J. C. Deng; P. Jin; HEBEI INST OF TECH TIANJIN (CHINA)
|
| InGaAsP/InP multiple quantum wells have been prepared by Impurity-Free Vacancy Disordering (IFVD). The luminescent characteristics was investigated using photoluminescence (PL) and photoreflectance (PR), from which the band gap blue shift was observed. SiN4, SiO2 and SOG were used for the dielectric layer to create the vacancies. All samples were annealed by rapid thermal annealing (RTA). The results indicate that the band gap blue shift varies with the dielectric layers and ... |
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| High Luminescence Efficiency from GaAsN Layers Grown by MBE with RF Nitrogen Plasma Source |
JAN 2002 |
6 pages |
| Authors:
Victor M. Ustinov; Nikolai A. Cherkashin; Nikolai A. Bert; Andrei F. Tsatsul'nikov; Alexei R. Kovsh; RUSSIAN ACADEMY OF SCIENCES SAINT PETERSBURG IOFFE PHYSICAL-TECHNICAL INST
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| (In)GaAsN based heterostructures have been found to be promising candidates for the active region of 1.3 micron VCSELs. However (In)GaAsN bulk layers and quantum wells usually demonstrate lower photoluminescence intensity than their nitrogen-free analogues. Defects associated with lower temperature growth and N-related defects due to plasma cell operation and possible nonuniform distribution of nitrogen enhance the non-radiative recombination in N-contained layers. We studied the photoluminescence intensity of GaAsN layers as ... |
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| Effect of Rapid Thermal Annealing: Red and Blue Shift in Photoluminescence of GaNAs Grown by RF Plasma-Assisted Molecular Beam Epitaxy |
JAN 2002 |
6 pages |
| Authors:
W. K. Loke; S. F. Yoon; T. K. Ng; S. Z. Wang; W. J. Fan; NANYANG TECHNOLOGICAL INST (SINGAPORE)
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| Rapid thermal annealing (RTA) of 1000A GaNAs films grown on (100) oriented GaAs substrate by radio frequency (RF) plasma assisted solid-source molecular beam epitaxy was studied by low-temperature photoluminescence (PL) and high-resolution x-ray diffraction (HRXRD). Samples with nitrogen content of 1.3 and 2.2% have shown an overall blueshift in energy of 67.7 meV and an intermediate redshift of 42.2 meV in the PL spectra when subjected to RTA at 529-850 ... |
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| InAsN Grown by Plasma-Assisted Gas Source MBE |
JAN 2002 |
6 pages |
| Authors:
Ding-Kang Shih; Hao-Hsiung Lin; Tso-Yu Chu; T. R. Yang; NATIONAL TAIWAN UNIV TAIPEI
|
| We report the structural, electrical and optical properties of bulk InAsN alloy with various nitrogen contents deposited on (100) InP substrates by using plasma-assisted gas source molecular beam epitaxy. It is found that the fundamental absorption edge of InAsN, as compared to that of InAs, shifts to higher energy due to Burstein-Moss effect. A dramatic increase of the electron effective mass in a nitrogen-containing III-V alloy is also observed from ... |
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| Near Field Microscopy and Spectroscopy of Photonic Nanostructures |
01 DEC 2001 |
8 pages |
| Authors:
Howard E. Jackson; Joseph T. Boyd; CINCINNATI UNIV OH
|
| This program involved research on the utilization of near field optical microscopic and spectroscopic techniques to investigate spatial configurations on a nanometer scale of both integrated photonic structures and semiconductor nanostructures. We have made significant accomplishments in our research effort involving use of these near field techniques to investigate several important areas including photonic bandgap structures or photonic crystals, vertical cavity surface emitting lasers (VCSEL's), and optical waveguides including multiple ... |
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| Surfactant Templated Assembly of Hexagonal Mesostructured Semiconductors Based on Ge4Q104- (Q=S, Se) and Pd2+ and Pt2+ Ions |
NOV 2001 |
6 pages |
| Authors:
Pantelis N. Trikalitis; Krishnaswamy K. Rangan; Mercouri G. Kanatzidis; MICHIGAN STATE UNIV EAST LANSING DEPT OF CHEMISTRY
|
| Mesostructured semiconducting non-oxidic materials were prepared by linking Ge4Q10(4-)(Q=S, Se) clusters with the square planar noble metal cations of Pd(2+) and Pt(2+) in the presence of cetylpyridinium surfactant molecules. The use of Pt(2+) afforded materials with exceptionally high hexagonal pore order similar to those of high quality silica MCM-41. These materials are semiconductors with energy band gap in the range 1.8 < E(sub g) < 2.5 eV. |
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| Magic Family of Discretely Sized Ultrabright Si Nanoparticles |
NOV 2001 |
6 pages |
| Authors:
G. Belomoin; J. Therrien; A. Smith; S. Rao; R. Twesten; ILLINOIS UNIV AT URBANA
|
| We describe a procedure for dispersion bulk Si into a family discretely sized ultrasmall ultrabright nanoparticles. We demonstrate that electrochemically etched, hydrogen capped Si(n)H(x), clusters with n larger than 20 are obtained within a family of discrete sizes. These sizes are 1.0 (Si29), 1.67 (Si123), 2.15, 2.9, and 3.7 nm diameter. We characterize the particles via direct electron imaging, excitation and emission optical spectroscopy, chromatography, and colloidal crystallization. The band ... |
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| Optical Characterization and Modeling of Sulfur Incorporated Nanocrystalline Carbon Thin Films Deposited By Hot Filament CVD |
NOV 2001 |
7 pages |
| Authors:
S. Gupta; B. R. Weiner; G. Morell; PUERTO RICO UNIV SAN JUAN DEPT OF PHYSICS
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| Sulfur incorporated nanocrystalline carbon (n-C:S) thin films grown on molybdenum substrates by hot-filament chemical vapor deposition (HFCVD) using gas mixtures of methane, hydrogen and a range of hydrogen sulfide (H2S) concentrations are optically examined using Raman spectroscopy (RS) and ex sin? spectroscopic phase modulated ellipsometry (SPME) from near IR to near UV (1.5-5.0 eV) obtaining their vibrational frequencies and pseudodielectric function, respectively. The ellipsometry data (< epsilon(sub r)(E) >, < ... |
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| Optical Nonlinearity of Sputtered Co3O4-SiO2-TiO2 Thin Films |
NOV 2001 |
5 pages |
| Authors:
Hiroki Yamamoto; Takashi Naito; Kazuyuki Hirao; KYOTO UNIV (JAPAN)
|
| Optical non-linearity of cobalt oxide with SiO2-TiO2 additives was investigated, and the change mechanism of the refractive index (n) and extinction coefficient (k), based on the relation between band structure and optical non-linearity of the thin films, was discussed. Refractive index and extinction coefficient of Co3O4 thin films in the ground state were 3.17 and 0.42, respectively. Both n and k decreased by irradiation from a pulse laser with 650 ... |
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| Catalyst-Free Growth of Large Scale Ga2O3 Nanowires |
NOV 2001 |
6 pages |
| Authors:
Ko-Wei Chang; Sai-Chang Liu; Liang-Yih Chen; Franklin C. Hong; Jih-Jen Wu; NATIONAL CHENG KUNG UNIV TAINAN (TAIWAN) DEPT OF CHEMICAL ENGINEERING
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| Large scale of straight Ga2O3 nanowires is grown on a fused silica substrate by a simple catalyst-free CVD method using Ga metal and N2/H2O reactants. The Ga2O3 nanowires with diameters ranging from 60 to 150 nm can be as long as several micrometers. XRD and TEM analyses indicate that the Ga2O3 nanowires exhibit a monoclinic structure. PL characteristic of the Ga2O3 nanowires shows a UV emission of 375 nm at ... |
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| UV/Blue III-Nitride Micro-Cavity Photonic Devices |
OCT 2001 |
10 pages |
| Authors:
Hongxing Jiang; Jingyu Lin; III-N TECHNOLOGY INC MANHATTAN KS
|
| Consistent with our tasks we have further improved our micro-size light emitter output efficiencies by optimizing device layer structures, including superlattice structures for enhancing the hole concentration, the thickness of the top Mg doped p-type layer to reduce the light absorption, and the structure of the active region. We have also carried out measurements on the size dependence of the micro-size light emitter characteristics. It was found that the micro-LEDs ... |
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| UV/Blue III-Nitride Micro-Cavity Photonic Devices |
31 AUG 2001 |
8 pages |
| Authors:
Hongxing Jiang; Jingyu Lin; III-N TECHNOLOGY INC MANHATTAN KS
|
| Consistent with our tasks, we have further improved our micro-size light emitter output efficiencies by optimizing device layer structures, including superlattice structures for enhancing the hole concentration, the thickness of the top Mg doped p-type layer to reduce the light absorption, and the structure of the active region. We have also carried out measurements on the size dependence of the micro-size light emitter characteristics. It was found that the micro-LEDs ... |
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| UV/Blue III-Nitride Micro-Cavity Photonic Devices |
13 JUL 2001 |
6 pages |
| Authors:
Hongxing Jiang; Jingyu Lin; III-N TECHNOLOGY INC MANHATTAN KS
|
| The main objective of this Phase I research is to further develop III-nitride microcavity photonics device technologies. Consistent with our tasks, we have further improved our light emitter output efficiencies by optimizing device layer structures, including superlattice structures for enhancing the hole concentration, the thickness of the top Mg doped p-type layer to reduce the light absorption, and the structure of the active region. We have also carried out preliminary ... |
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| Nanostructures: Physics and Technology |
JUN 2001 |
634 pages |
| Authors:
RUSSIAN ACADEMY OF SCIENCES ST PETERSBURG IOFFE PHYSICAL- TECHNICAL INST
|
| The Proceedings of the 9th International Symposium on Nanostructures: Physics and Technology (NANO200l) held in St. Petersburg, Russia on June 18-22 2001 contains papers on the following topics: Nanostructure technology, Silicon based nanostructures, Infrared phenomena in nanostructures, Wide band gap nanostructures, Microcavity and photonic crystal, Nanostructure characterization and novel atomic-scale probing techniques, Quantum wells and superlattices, Quantum wires and quantum dots, Tunneling phenomena, General properties of low dimensional structures, Spin ... |
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| Interaction in the Final State of the Interface Luminescence with Delta-Doped Layers |
JUN 2001 |
2 pages |
| Authors:
A. Yu. Silov; N. S. Averkiev; P. M. Koenraad; J. H. Wolter; EINDHOVEN UNIV OF TECH (NETHERLANDS) COBRA RESEARCH GROUP
|
| We show that Coulomb interaction within a delta-layer of donors is governed by the neighboring two-dimensional hole gas. It has been found experimentally that the interface luminescence band displays pronounced blue shift when the two-dimensional holes recombine with delta-donors. Our analysis confirms that uniform distribution of the delta-dopants provides adequate description of the energy shift versus excitation level. |
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| Effect of Additional Illumination on the Kinetics of Exciton Complex Formation in the Quantum Wells of Undoped GaAs/AlGaAs Structures |
JUN 2001 |
5 pages |
| Authors:
N. N. Sibeldin; M. L. Skorikov; V. A. Tsvetkov; RUSSIAN ACADEMY OF SCIENCES MOSCOW (RUSSIA) LEBEDEV INST
|
| Low-temperature (T = 2K) photoluminescence (PL) and photoluminescence excitation (PLE) spectra of GaAs/ AlGaAs (x = 0.05) structures with shallow quantum wells (QW) and the effect of additional illumination by He-Ne laser radiation on these spectra were investigated. It was found that the PLE spectra exhibit a number of broad bands in the above-barrier energy region; these bands alternate "in opposite phases" in the spectra of free excitons and excitonic ... |
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| 3D Digital Data-Storage Using Two-Photon Process: A Demonstration Task/ Novel Multifunctional Chromophores for Electro-Optic and Other Photonics Applications |
JUN 2001 |
8 pages |
| Authors:
Paras N. Prasad; STATE UNIV OF NEW YORK AT ALBANY RESEARCH FOUNDATION
|
| New opto-electronic and composite materials with enhanced photonic performance were developed and that applicators in 3D optical data-storage, 3D optical-circuitry, 3D micro-fabrications and photorefractivity were studied. Two-photo based technology was used to do photo-crosslinking at a precise volume location to produce complex 3D opticalcircuitry such a waveguide splitters and grating couplers as well as for fabricating MEMS. Another area of our activity bas been in preparation of photonic band gap ... |
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| International Workshop on Amorphous and Nanostructured Chalcogenides. Fundamentals and Applications (1st) held in Bucharest, Romania on 25-28 June 2001. Proceedings, Part 1 |
JUN 2001 |
|
| Authors:
Mihai A. Popescu; NATIONAL INST OF MATERIALS PHYSICS BUCHAREST (ROMANIA)
|
| Includes papers presented at the First International Workshop on Amorphous and Nanostructured Chalcogenides Fundamentals and Applications held in Bucharest, Romania June 25-28, 2001. |
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| Comparison of Dye Photoluminescence Spectra in Direct and Inverted Opaline Films |
JUN 2001 |
3 pages |
| Authors:
S. G. Romanov; T. Maka; C. M. Sotomayor-Torres; M. Mueller; R. Zentel; RUSSIAN ACADEMY OF SCIENCES SAINT PETERSBURG IOFFE PHYSICAL-TECHNICAL INST
|
| Changes introduced by a photonic bandgap environment in an emission spectrum of a light source have been compared for direct and inverted opals and a qualitative difference has been revealed. |
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| GBS IOTE Feed Measurements |
23 MAY 2001 |
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| Authors:
T. W. Borge; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
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| The Ka-Band (30/20 GHz) terminal was used to conduct I, O, T, and E of the Global Broadcast System (GBS) package on UHF Follow-on (UFO) satellites, flights 8, 9, and 10. This terminal has been transferred to Lincoln Laboratory through the Milsatcom Joint Program Office at the USAF Space and Missile Center (AFSMC). At Lincoln Laboratory, the terminal is to be evaluated for possible use in on-orbit checkout/experimentation with the ... |
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| Resonant Interband Tunnel Diodes with AlGaSb Barriers |
15 MAY 2001 |
4 pages |
| Authors:
R. Magno; A. S. Bracker; B. R. Bennett; NAVAL RESEARCH LAB WASHINGTON DC
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| The peak current density of InAs/AlSb/GaSb/AlSb/InAs resonant interband tunneling diodes (RITDs) has been enhanced by replacing the AlSb barriers with Al(1-x)Ga(x)Sb that has a narrower band gap. The devices were grown by molecular beam epitaxy and tested at room temperature. Diodes with nominally identical 7-ML-thick ternary alloy barriers with x=0.35 are found to have peak current densities three times larger than those with AlSb barriers. The peak-to-valley current ratio decreases ... |
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| In- and Out-of-Plane Propagation of Electromagnetic Waves in Low Index Contrast Two Dimensional Photonic Crystals |
15 JAN 2001 |
8 pages |
| Authors:
S. Foteinopoulou; A. Rosenberg; M. M. Sigalas; C. M. Soukoulis; AMES LAB IA
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| Propagation of electromagnetic waves through a two-dimensional triangular lattice has been studied for different values of refractive index contrast between the constituent dielectrics, and for angles of incidence both in and out of the plane of periodicity. Transmission results have been obtained both experimentally and with the transfer matrix technique, and good agreement has been found between the two. Comparison with band structure calculations has also been made. |
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| Growth and Characterization of Single Crystals of Ternary Chalcogenides for Laser Applications |
2001 |
9 pages |
| Authors:
Ludmila Isaenko; Alexander Yelisseyev; Jean-Jacques Zondy; Guido Knippels; I. Thenot; DESIGN AND TECHNOLOGICAL INST OF MONOCRYSTALS NOVOSIBIRSK (RUSSIA)
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| Bulk single crystals up to 20 mm in diameter and 40 mm long for LiInS2 and up to 10 mm, 20 mm, respectively, for LiInSe2 have been grown. Their color changed from colorless to rose for the first one and from yellow to dark red for the other. All crystals have wurtzite-type lattice (Pna21 space group), lattice parameters were determined. A band gap was found to be 3.72 and 3.57 ... |
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| Low Cost Microengineered Functional IR Material |
01 DEC 2000 |
87 pages |
| Authors:
Albert Green; SCIENCE APPLICATIONS INTERNATIONAL CORPMCLEAN VA
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| This report documents an approach to fabricating large area, low cost 3-D photonic crystal structures using continuously web compatible techniques. We document and detail a process that involves microembossing, differential stripping, direct transfer, and alignment. We also discuss an analytical technique that can be used to model the reflectance and transmittance of multilayer structures. The principle goal of SAIC's Highly Controlled Dielectric Emissivity (HIDE) program was to apply the techniques ... |
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| International Workshop on Light-Matter Coupling in Nitrides Held in St. Nectaire, France on Oct. 8-12, 2000 |
12 OCT 2000 |
199 pages |
| Authors:
Alexey Kavokin; Bernard Gil; CLERMONT-FERRAND-2 UNIV AUBIERE (FRANCE)
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| A One-Dimensional Photonic Bandgap System as High-Reflectivity Mirror for Microwave and THz Applications |
29 SEP 2000 |
4 pages |
| Authors:
Gerhard W. Schwaab; RUHR-UNIV BOCHUM (GERMANY) LEHRSTUHL FUR PHYSIKALISCHE CHEMIE
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| A one-dimensional photonic bandgap mirror (PBM) has been designed consisting of periodically alternating planar quarter-wavelength layers of a high-refractive index dielectric and low-refractive index material (e.g. vacuum). A V-shaped folded Fabry-Perot Interferometer was set up with two scaled PBMs and a spherical metal mirror to provide a stable resonator design. The PBMs consisted of polystyrene and air as dielectrics and were designed for a center frequency of 23.44 GHz. The ... |
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| Progress in Heterostructure Barrier Varactor Frequency Multipliers |
29 SEP 2000 |
4 pages |
| Authors:
Jan Stake; Mattias Ingvarson; Lars Dillner; Erik Kollberg; CHALMERS UNIV OF TECHNOLOGY GOETEBORG (SWEDEN) DEPT OF MICROELECTRONICS
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| The Heterostructure Barrier Varactor diode and its performance as a varactor frequency multiplier is reviewed. |
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Reports by Keyword(s)
BAND GAPS
