Performance of an embedded optical vector matrix multiplication processor architecture

An embedded architecture of optical vector matrix multiplier (OVMM) is presented. The embedded architecture is aimed at optimising the data flow of vector matrix multiplier (VMM) to promote its performance. Data dependence is discussed when the OVMM is connected to a cluster system. A simulator is built to analyse the performance according to the architecture. According to the simulation, Amdahl's law is used to analyse the hybrid opto-electronic system. It is found that the electronic part and its interaction with optical part form the bottleneck of system.

硅薄膜太阳电池的背反陷光研究

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-07T07:19:43Z No. of bitstreams: 1 肖海波硕士论文.pdf: 2484750 bytes, checksum: 56e9dbca921b11e876dee06953ad6f45 (MD5)

Low-threshold diode-pumped CW passively mode-locked Nd:YVO4 lase

A low-threshold passively continuous-wave (CW) mode-locked Nd:YVO4 solid-state laser was demonstrated by use of a semiconductor saturable absorber mirror (SESAM). The threshold for continuous-wave mode-locked is relatively low, about 2.15 W. The maximum average output power was 2.12 W and the optical to optical conversion efficiency was about 32%. The pulse width was about 15 ps with the repetition rate of 105 MHz. (C) 2008 Elsevier GmbH. All rights reserved.

Quantifying the effectiveness of SiO2/Au light trapping nanoshells for thin film poly-Si solar cells

In order to enhance light absorption of thin film poly-crystalline silicon (TF poly-Si) solar cells over a broad spectral range, and quantify the effectiveness of nanoshell light trapping structure over the full solar spectrum in theory, the effective photon trapping flux (EPTF) and effective photon trapping efficiency (EPTE) were firstly proposed by considering both the external quantum efficiency of TF poly-Si solar cell and scattering properties of light trapping structures. The EPTF, EPTE and scattering spectrum exhibit different behaviors depending on the geometric size and density of nanoshells that form the light trapping layer. With an optimum size and density of SiO2/Au nanoshell light trapping layer, the EPTE could reach up to 40% due to the enhancement of light trapping over a broad spectral range, especially from 500 to 800 nm.

Structural and magnetic properties of GaN:Sm:Eu films fabricated by co-implantation method

Diluted-magnetic GaN:Sm:Eu films have been fabricated by co-implantation of Sm and Eu ions into c-plane (0001) GaN films and a subsequent annealing process. The structural, morphological and magnetic characteristics of the samples have been investigated by means of high-resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), and superconducting quantum interference device (SQUID). The XRD and AFM analyses show that the annealing process can effectively recover the crystalline degradation caused by implantation. Compared with GaN:Sm films, more defects have been introduced into GaN:Sm:Eu films due to the Eu implantation process. According to the SQUID analysis, GaN:Sm:Eu films exhibit clear room-temperature ferromagnetism. Moreover, GaN:Sm:Eu films show a lower saturation magnetization (Ms) than GaN:Sm films.

Variation of Optical Quenching of Photoconductivity with Resistivity in Unintentional Doped GaN

The optical quenching of photoconductivity under dual illumination in GaN samples with different resistivity is investigated to reveal the variation of deep levels. The samples are grown by metal organic chemical vapour deposition without intentional doping. Quenching bands centered at 1.35 eV, 1.55 eV, 1.98 eV, and 2.60 eV are observed. It is found that the 1.98 eV quenching band is dominated in all the samples and the 2.60 eV band is observed only in the high-resistivity samples. The possible defect levels responsible for the quenching bands and the origin of different quenching behaviour at 2.60 eV are discussed. It is suggested that the defect level responsible for quenching at 2.60 eV plays an important role for the enhancement of resistivity.

Anomalous shift of the beating nodes in illumination-controlled In1-xGaxAs/In1-yAlyAs two-dimensional electron gases with strong spin-orbit interaction

The beating patterns in the Shubnikov-de Haas oscillatory magnetoresistance originating from zero-field spin splitting of two-dimensional electron gases (2DEGs) in In0.52Al0.48As/InxGa1-xAs/In0.52Al0.48As quantum wells with silicon delta doped on the upper barrier layer have been investigated by means of magnetotransport measurements before and after illumination. Contrary to the expectation, after each illumination, the beating nodes induced by the zero-field spin-splitting effect shift to lower and lower magnetic field due to the decrease in the zero-field spin-splitting energy of the 2DEGs. The anomalous phenomenon of the shift of the beating nodes and the decrease in spin-orbit coupling constants after illumination cannot be explained by utilizing the previous linear Rashba model. It is suggested that the decrease in the zero-field spin-splitting energy and the spin-orbit coupling constant arise from the nonlinear Rashba spin splitting.

非极性GaN基稀磁半导体的制备与性质研究

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-02T01:49:46Z No. of bitstreams: 1 孙莉莉博士毕业论文.pdf: 4262097 bytes, checksum: 1e7491172a0ed5e5117f934a6b9652a1 (MD5)

Donor defect in P-diffused bulk ZnO single crystal

A high concentration of shallow donor defect is formed in P-diffused ZnO single crystals. X-ray photoelectron spectroscopy analysis indicates that P atom occupy different lattice site at different diffusion temperature. Nature of the donor defect has been discussed.

InGaN基发光二极管的反常特性研究

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-02T02:11:24Z No. of bitstreams: 1 丁凯博士学位论文.pdf: 16795233 bytes, checksum: 311ac7bbd9c83be13609a0a0f4b36268 (MD5)

立方相碳化硅高量程微机械加速度计研究

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-07T01:08:53Z No. of bitstreams: 1 立方相碳化硅高量程微机械加速度计研究.pdf: 2551518 bytes, checksum: c103d007add79adccfc0be58903561c6 (MD5)

四针状氧化锌晶须吸波涂层的制备与研究

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-08T12:54:01Z No. of bitstreams: 1 马泽宇-四针状氧化锌晶须吸波涂层的制备与研究.pdf: 1372183 bytes, checksum: 30e24d73348a7814510ac6f0039734ef (MD5)

InGaN 太阳能电池理论模拟及制备研究

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-08T12:57:05Z No. of bitstreams: 1 毕业论文-张小宾.pdf: 4412903 bytes, checksum: f96f6b7c0b4a1341e050825b566caddd (MD5)

MOCVD设备研制及氮化物材料生长研究

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-08T13:11:28Z No. of bitstreams: 1 MOCVD设备研制及氮化物材料生长研究—殷海波-200718013626085.pdf: 3776668 bytes, checksum: efab1d75bd6d03744fd23a7a554f17e7 (MD5)

MVPE Ga 掺杂ZnO 薄膜材料的制备及其在LED 中的应用

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-13T08:11:59Z No. of bitstreams: 1 硕士论文－刘祯.pdf: 1866687 bytes, checksum: 88d4171893f5d652dc81f3bda540b7bf (MD5)