利用轫致辐射能谱测定高频腔体电压

报道了利用轫致辐射能谱测定高频腔体电压的原理、方法及结果分析，并与直接测量法的结果进行比较，说明这种间接测定法的优点。通过实际调束流轨道、能量的测定与计算验证了用能谱法测定腔体电压数值的准确可靠性。     

设备制造商应思考的新问题

讨论了面对半导体产业的新形势,设备制造商应思考新问题和寻找新产品;并指出半导体设备的新发展趋势,如设备的模块化、软件化和多功能化。     

图示仪在LED失效分析中的应用

本文基于图示仪的检测原理,说明了其测量LED参数的方法,提出了在LED失效分析中图示仪几个特殊的应用和操作方法.     

Colossal and constant magnetoresistance over a large temperature range between 230 and 4.2 K in La0.8Li0.2MnO3 prepared by a partial melting technique

La_0.8Li_0.2MnO₃ was prepared by a partial melting technique. The Li-doped LaMnO₃ compound has a rhombohedral perovskite structure and shows a wide semiconductor-to-metal transition between 230 and 175 K in resistance versus temperature. Nearly constant magnetoresistance, Δρ/ρ₀, above 20–60% was achieved with application of magnetic fields from 1 to 8 Tesla (T) over a very large temperature range from the ferromagnetic transition at 230–4.2 K. As a comparison, a partial melted La_0.7Ca_0.3MnO₃ shows a very narrow ferromagnetic transition around 230 K which is the same as that of single crystals and epitaxy thin films.     

Electrochemical C-V Characteristics and Photoluminescence of a-C∶N Films

Amorphous carbon (a-C) films and amorphous carbon films incorporating with the nitrogen (a-C∶N) were deposited on silicon substrates in a radio-frequency driven plasma enhanced chemical vapour deposition system, while the surface electrical properties of films were investigated by electrochemical capacitance-voltage measurements. It was examined the effect of the interface defects on the properties and deduced that the conducting type of a-C∶N films was n-type. Subsequently, a comparative studies of a-C and a-C∶N films were performed by photoluminescence spectra depending on the temperature. With the decrease of the temperature, the main band with peak energy of 2.48 eV in the a-C∶N films was more intense compared with the other three bands caused by amorphous C in the a-C films.     

半导体激光联合电针及康复干预治疗周围性面神经炎的疗效观察

目的:观察半导体低强度激光联合电针及康复干预治疗周围性面神经炎的临床疗效。方法:将急性周围性面神经炎患者76例,随机分成对照组和观察组各38例。对照组给予电针加早期康复干预;观察组在此基础上加用半导体激光仪照射治疗。评价治疗前后两组患者面神经功能及治疗后其临床疗效。结果:干预3周后,两组患者面神经功能评分均比治疗前明显提高(P<0.05);且观察组更高于对照组(P<0.05);干预后,两组疗效有显著差异(P相似文献   

Performance assessment of multijunction solar cells incorporating GaInNAsSb

We have measured the characteristics of molecular beam epitaxy grown GaInNAsSb solar cells with different bandgaps using AM1.5G real sun illumination. Based on the solar cell diode characteristics and known parameters for state-of-the-art GaInP/GaAs and GaInP/GaAs/Ge cells, we have calculated the realistic potential efficiency increase for GaInP/GaAs/GaInNAsSb and GaInP/GaAs/GaInNAsSb/Ge multijunction solar cells for different current matching conditions. The analyses reveal that realistic GaInNAsSb solar cell parameters, render possible an extraction efficiency of over 36% at 1-sun AM1.5D illumination.

PACS

88.40.hj; 88.40.jm; 88.40.jp; 81.15.Hi     

Visible and infrared emission from Si/Ge nanowires synthesized by metal-assisted wet etching

Abstract

Multi-quantum well Si/Ge nanowires (NWs) were realized by combining molecular beam epitaxy deposition and metal-assisted wet etching, which is a low-cost technique for the synthesis of extremely dense (about 10¹¹ cm⁻²) arrays of NWs with a high and controllable aspect ratio. In particular, we prepared ultrathin Si/Ge NWs having a mean diameter of about 8 nm and lengths spanning from 1.0 to 2.7 μm. NW diameter is compatible with the occurrence of quantum confinement effects and, accordingly, we observed light emission assignable to the presence of Si and Ge nanostructures. We performed a detailed study of the photoluminescence properties of the NWs, with particular attention to the excitation and de-excitation properties as a function of the temperature and of the excitation photon flux, evaluating the excitation cross section and investigating the presence of non-radiative phenomena.

PACS

61.46.Km; 78.55.-m; 78.67.Lt     

Copper selenide nanorods grown at room temperature by electrodeposition

In this work we employed an electrodeposition technique to prepare copper selenide nanorods with various dimensions by changing bath concentration and keeping deposition time fixed. This study reports the effect of bath concentration on the crystal structure, surface morphology and optical properties of copper selenide thin films. The electrodeposited films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectra properties, the ultraviolet–visible (UV–vis) and compositional analysis. Upon bath concentration, the band gap energy of copper selenide decreases from 2.54 eV to 2.35 eV along with an increase in the crystal size form 7–17 nm. The crystal size was found to increase upon increase in bath concentration and materials exhibit better crystallization. Similar results were also observed in the XRD studies, where peak intensity increased upon bath concentration.