DETERMINATION OF TOTAL EL2 AND NET ACCEPTOR CONCENTRATION IN UNDOPED SI GaAs BY MULTI-WAVELENGTH INFRARED ABSORPTION METHOD

Total EL2 concentration distribution and net acceptor concentration distribution in uncloped semi-insulating(SI) LEC GaAs have been measured by multi-wavelength infrared absorption method. The experimental results indicate that total EL2 concentration radial distribution is W-shaped and net acceptor concentration radial distribution is sample-dependent, it can present a n shape, a A shape, or a W shape corresponding to different samples.     

Thermal Annealing and Propagation of Shockley Stacking Faults in 4H-SiC PiN Diodes

Stacking faults within 4H-SiC PiN diodes are known to be detrimental to device operation. Here, we present electroluminescence (EL) images of 4H-SiC PiN diodes providing evidence that electrically and optically stimulated Shockley stacking fault (SSF) propagation is a reversible process at temperatures as low as 210°C. Optical beam induced current (OBIC) images taken following complete optical stressing of a PiN diode and that lead to a small number of completely propagated SSFs provide evidence that such defects propagate across the n–/p+ interface and continue to grow throughout the p+ layer. These observations bring about questions regarding the validity of the currently accepted driving force mechanism for SSF propagation.     

哈锅660MW高效超超临界循环流化床锅炉方案研究

在传统能源的清洁高效开发、转化、利用为主要发展的趋势下,更低供电煤耗和超低污染物排放将是火电机组未来发展方向,开发更高蒸汽参数的循环流化床锅炉是流化床技术发展的客观需求.本文论述了哈锅开发的660MW高效超超临界循环流化床锅炉的技术路线和技术方案,重点对锅炉的炉型选择、布置特点、系统配置、以及水动力、外置床、循环回路均...     

基于T型中点钳位的单向混合三相电压型整流器

分析当前的单向混合三相电压型整流器(UHTPVSR)的拓扑结构和工作原理,并对其拓扑结构进行改进。提出基于T型中点钳位(TNPC)的单向混合三相电压型整流器拓扑结构,分别建立了Boost变换器和TNPC整流器的Euler-Lagrange(EL)模型,基于此模型,采用外环PI,内环无源的无源混合控制策略。在Matlab/Simulink中建立模型进行仿真,仿真结果说明无源混合控制策略具有强鲁棒性、动态性能好、抗干扰能力强等优点。     

±660kV直流换流站阀厅内金具表面电场数值求解

针对我国特有的±660kV的电压等级下的阀厅全模型的金具电场计算,采用静电场瞬时加载法,首先根据±660kV换流站阀厅换流变压器设备参数,通过MATLAB仿真得到阀厅内部主要设备在额定功率以及轻载功率下的电位波形,选取比较典型的16组数据进行数值求解,从而得到相应情况下阀厅内部场强最大值以及场强变化曲线。计算结果表明,...     

化工厂低压配电采用660V供电技术探讨

本文针对化工厂采用660V电压等级进行可行性分析,阐述采用660V电压等级的意义。     

新型低压高效叠层有机白光器件

以Bphen:Li/WO3作为电荷产生层制备了低压、高效有机叠层白光器件. 实验中,首先在器件中引入高导电性的载流子注入和传输层,有效降低了器件的驱动电压,然后通过电荷产生层垂直堆叠两个低压白光器件,获得了低压、高效有机叠层白光器件. 叠层器件性能与单发光单元的器件相比较,其亮度及效率均有大幅提高,叠层器件的最大电流效率达到了17cd/A,在相同的电流密度下,叠层器件的效率约为传统器件的2.3倍,同时由于在叠层结构中引入了高导电性的载流子传输层,有效降低了器件的驱动电压,显著改善了白光器件的流明效率.叠层器件的流明效率相对于单发光单元器件提高了53%.     

660MW超超临界机组辅机单列布置的安全性与经济性探讨

布连电厂660 MW超超临界机组辅机采用单列布置方式,将其安全性、运行经济性与采用辅机双列布置的机组进行对比,结果表明,机组辅机单列布置在初投资、运行维护、设备检修等费用方面能够大幅度节约投资,生产运行期间的低负荷经济性较高,并且不存在辅机双列布置时2台风机在低负荷运行期间发生"抢风"的不稳定运行状况。同时,随着单列布置的辅机设备及热工控制系统性能的提高,辅机单列布置的机组的安全性与稳定性将显著提高。本文可为发电企业在新建机组辅机设计及布置选型方面提供技术参考。     

A study on the origin of emission of the annealed n-ZnO/p-GaN heterostructure LED

We report the effects of thermal annealing in air and N₂ ambient on the structural, optical, and electrical properties of zinc oxide (ZnO) films deposited on a p-GaN substrate. Also, we report on the fabrication and device characterization of heterojunction light-emitting diodes based on the n-ZnO/p-GaN systems. In the case of N₂ ambient, room-temperature electroluminescence (EL) in the violet region with peak wavelength 400 nm was observed under forward bias. In air ambient, EL spectrum consisted of a broad band from 400 nm to 700 nm due to the Ga-O mixed region formed interface between the ZnO and GaN layer.     

有机电致发光屏显示模块研究

通过对有机电致发光器件的结构以及发光机理的分析，介绍了一种以内藏式图形控制器T6963C为主控制芯片的0LED显示模块，并给出了该显示模块与单片机的接口以及软件控制流程。