Fabrication and characterization of metal-semiconductor-metal (MSM) ultraviolet photodetectors on undoped GaN/sapphire grown by MBE

Interdigital metal-semiconductor-metal (MSM) ultraviolet photoconductive detectors have been fabricated on undoped GaN films grown by molecular beam epitaxy (MBE), Response dependence on wavelength, applied current, excitation powers and chopper frequency has been extensively investigated. It is shown that the photodetector's spectral response remained nearly constant for wavelengths above the band gap and dropped sharply by almost three orders of magnitude for wavelengths longer than the band gap. It increases linearly with the applied constant current, but very nonlinearly with illuminating power. The photodetectors showed high photoconductor gains resulting from trapping of minority carriers (holes) at acceptor impurities or defects. The results demonstrated the high quality of the GaN crystal used to fabricate these devices. (C) 2000 Elsevier Science B.V. All rights reserved.

COM组件技术在CSR控制系统中的应用

HIRFL-CSR（兰州重离子冷却储存环）是国家重点实验室之一。CSR控制系统是保证CSR正常运行的重要环节。这样一个大型的控制系统，是由多个子系统分别构成的。在CSR的控制方案中，允许用户通过访问web浏览器并利用COM技术来控制设备和获知设备的当前运行情况。本文描述了一个典型子系统中设备控制的实现。并介绍了COM更高层次的应用，即DCOM技术在分布式领域的应用。一本文首先介绍了Windows编程，Win32应用程序等一些基本的编程知识，并且简单介绍了开发COM组件的开发工具ATL和COM组件的基本概念。其次，介绍了一个具体子系统的软件结构和整体设计。最后详细介绍了DCOM技术的基本结构，和它所提供的一些系统服务。整个论文的工作介绍了CSR控制子系统中COM组件技术的选择理由，并完成了COM组件的程序设计和软件调试。还为以后开发和实现分布式控制系统的控制组件提供了理论基础知识。