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1.
本文计算了GaP/Au 反光镜, GaP/SiO2/Au 三层ODR and GaP/ITO/Au 三层ODR的反射率随角度的变化值。制作了GaAs衬底的AlGaInP LED,Au反光镜、SiO2 ODR和ITO ODR的薄膜AlGaInP LED。在20mA下,四种样品光输出功率分别为1.04mW, 1.14mW, 2.53mW and 2.15mW。制作工艺退火后,Au扩散使Au/GaP反光镜的反射率降至9%。1/4波长的ITO和SiO2透射率不同造成了两种薄膜LED光输出功率不同。ITO ODR中加入Zn可以大大降低LED的电压,但并不影响LED的光输出。 相似文献
2.
Using the methods of molecular simulation and HyperChem v.5.0 programs (PM3 method), we carried out calculations of the principal spectroscopic characteristics and of the structure of the laurdan molecule in the ground and the first excited electronic states. The thermal static distribution of molecules over various possible orientations LE" BORDER="0"> of the plane of methyl groups relative to the plane of the naphthalene bicycle was taken into account. The energies and dipole moments of these electronic states have been calculated as functions of the torsion angle of methyl groups. The existence of an additional mechanism of electronic spectrum broadening is shown; it is associated with thermal mismatch of the equilibrium orientations of the rotational fragment of the molecule and with the dependence of the electron transition frequency on the degree of deviation of the angle LE" BORDER="0"> from the equilibrium value. The dependence of dipole moments on this angle has been found and calculated. This dependence is the strongest for the ground state. The maximum values of dipole moments in the ground and excited states are 4.0 and 7.6 D. 相似文献
3.
We have studied the spectral properties of luminescence of laurdan molecules in glycerin upon excitation at the red edge of the absorption band at different temperatures. The most significant red-wave shift of the spectra (LE" BORDER="0">10 nm) for the longwave band of dual fluorescence is observed depending on the excitation wavelength at a low temperature of 260 K when a solvent forms a fairly rigid matrix. At the same time, at increased temperatures of up to 370 K a small bathochromic shift and a change in the shape of the luminescence bands are also recorded reliably. Changes in the excitation spectra were observed when luminescence was recorded in the bands of the LE- and CT states. The difference spectrum responsible for the additional absorption that does not make a contribution to the longwave luminescence component has been isolated. The decay kinetics of both luminescence components have been measured and their expansions in decay constants have been analyzed. The experimental dependences obtained point to the complex mechanism of inhomogeneous broadening of spectra. 相似文献
4.
Shu‐Hui Yin Yufang Liu Wei Zhang Ming‐Xing Guo Peng Song 《Journal of computational chemistry》2010,31(10):2056-2062
In this work, the time‐dependent density functional theory (TDDFT) method was carried out to investigate the hydrogen‐bonded intramolecular charge‐transfer excited state of 2‐(4′‐N,N‐dimethylaminophenyl)imidazo[4,5‐b]pyridine (DMAPIP) in methanol (MeOH) solvent. All the geometric conformations of the ground state and locally excited (LE) state and the twisted intramolecular charge‐transfer (TICT) state for isolated DMAPIP and its hydrogen‐bonded complexes have been optimized. At the same time, the absorption and fluorescence spectra of DMAPIP and the hydrogen‐bonded complexes in different electronic states are also calculated. We theoretically demonstrated for the first time that the intermolecular hydrogen bond formed between DMAPIP and MeOH can induce the formation of the TICT state for DMAPIP in MeOH solvent. Therefore, the two components at 414 and 506 nm observed in the fluorescence spectra of DMAPIP in MeOH solvent were reassigned in this work. The fluorescence peak at 414 nm is confirmed to be the LE state. Furthermore, the red‐shifted shoulder at 506 nm should be originated from the hydrogen‐bonded TICT excited state. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010 相似文献
5.
This letter presents a new one-dimensional chaotic map with infinite collapses. Theoretical analyses show that the map has complicated dynamical behavior and ideal distribution. The map can be applied in chaotic spreading spectrum communication and chaotic cipher. 相似文献
6.
Low-energy electron-enhanced etching of HgCdTe 总被引:3,自引:0,他引:3
Jaehwa Kim T. S. Koga H. P. Gillis Mark S. Goorsky Gerald A. Garwood John B. Varesi David R. Rhiger Scott M. Johnson 《Journal of Electronic Materials》2003,32(7):677-685
Low-energy electron-enhanced etching (LE4) is applied to HgCdTe to eliminate ion-induced surface damage. First, LE4 results
for patterned samples are illustrated. The LE4 mechanism is understood from a mechanistic study in terms of three etch variables:
direct current (DC) bias, gas composition, and sample temperature. For this paper, the effects of DC bias (electron energy)
and gas composition (CH4 concentration) are summarized qualitatively, followed by quantitative evidence. Etch rate, the amount of polymer, surface
stoichiometry, and surface roughness have specific relations with each etch variable under competition between pure LE4 and
polymer deposition. 相似文献
7.
H. P. Gillis D. A. Choutov K. P. Martin M. D. Bremser R. F. Davis 《Journal of Electronic Materials》1997,26(3):301-305
Hetero-epitaxial films of GaN(OOOl), deposited on SiC(OOOl) by organometallic vapor phase epitaxy and masked by 200 nm of
SiO2, have been patterned by low energy electron enhanced etching (LE4) in hydrogen and chlorine dc plasmas at room temperature.
Lines 2.0 μm wide showed highly anisotropic etching: straight side walls, no overcut, no trenching, and no “pedestal” at the
base of the line. Root mean square (RMS) surface roughness of the films as grown was 8.5–10?; after LE4, RMS surface roughness
of the etched surfaces was 2.5?. 相似文献
8.
WANG Yu-Sa CHEN Yong XU Yu-Peng WANG Juan CUI Wei-Wei LI Wei HAN Da-Wei ZHANG Zi-Liang CHEN Tian-Xiang LI Cheng-Kui YANG Yan-Ji LIU Xiao-Yan HUO Jia ZHANG Jun-Min ZHENG Yi-Qian 《中国物理C(英文版)》2010,34(12)
The Low Energy X-ray Instrument (LE) of the Hard X-ray Modulation Telescope (HXMT) uses the Swept Charge Device (SCD) to detect the X-rays in 1-15 keV. The performance of SCD is vulnerable to temperature. We analyzed the thermal condition of LE at different satellite working attitudes with the Finite Element Method (FEM). It is shown that the angle between the sunlight and the normal line of the barrier should be less them 26°, to keep the SCD detectors working in the required temperature range, i.e. -40 ℃ to -80 ℃. We find that the performance of LE is very stable in this temperature range, with a typical energy resolution of 160 eV at 5.9 keV. 相似文献
9.
10.
设计了一种基于STC90LE58RD+的GPS测量仪,讨论了系统硬件及软件设计方案,深入研究地球表面上不规则多边形区域的周长和面积的算法。文中通过硬件设计,利用GPS模块测得所在位置的经纬度,通过算法和软件实现不规则区域的周长和面积测量。应用文中的方法设计的GPS测量仪精度较高,且方便、快捷,有较好的使用价值。 相似文献