A series of hydrogenated silicon thin films were prepared by the radio frequency plasma enhanced chemical vapor deposition method (RF-PECVD) with various si-lane concentrations. The influence of silane concentration o...A series of hydrogenated silicon thin films were prepared by the radio frequency plasma enhanced chemical vapor deposition method (RF-PECVD) with various si-lane concentrations. The influence of silane concentration on structural and elec-trical characteristics of these films was investigated to study the phase transition region from amorphous to microcrystalline phase. At the same time,optical emis-sion spectra (OES) from the plasma during the deposition process were monitored to get information about the plasma properties,Raman spectra were measured to study the structural characteristics of the deposited films. The combinatorial analysis of OES and Raman spectra results demonstrated that the OES can be used as a fast method to diagnose phase transition from amorphous to microcrystalline silicon. At last the physical mechanism,why both OES and Raman can be used to diagnose the phase transition,was analyzed theoretically.展开更多
文摘针对非道路车辆尾气排放测试中常采用的一种便携式车载尾气排放测试系统(Portable Emissions Measurement System,PEMS)不能实时显示试验状态以及进度,造成试验冗余或不足等问题,设计了一种PEMS试验远程监测系统。该系统由车载端与远程端两部分组成,在基于SAE J1939通信协议下,车载端以C8051F120单片机为主控单元(Main Control Unit,MCU),实现了发动机电控单元(Electronic Control Unit,ECU)数据的解析、CAN总线上数据报文的接收与发送;远程端由C++Builder软件开发平台设计了一款人机交互界面,实现了发动机状态参数的实时显示、有效工作事件的筛选、试验累积功的计算以及试验进度显示等功能;同时车载端与远程端之间以无线方式进行通信。试验结果表明,采用本系统所得到的试验累积功的综合误差在±1.25%之内,证明所设计的系统不仅功能丰富而且具有较高的实时性、可靠性与稳定性,提高了PEMS试验的效率,具有较好的现实意义。
基金Supported by the National Basic Research Program of China (Grant Nos. 2006CB202602 and 2006CB202603)
文摘A series of hydrogenated silicon thin films were prepared by the radio frequency plasma enhanced chemical vapor deposition method (RF-PECVD) with various si-lane concentrations. The influence of silane concentration on structural and elec-trical characteristics of these films was investigated to study the phase transition region from amorphous to microcrystalline phase. At the same time,optical emis-sion spectra (OES) from the plasma during the deposition process were monitored to get information about the plasma properties,Raman spectra were measured to study the structural characteristics of the deposited films. The combinatorial analysis of OES and Raman spectra results demonstrated that the OES can be used as a fast method to diagnose phase transition from amorphous to microcrystalline silicon. At last the physical mechanism,why both OES and Raman can be used to diagnose the phase transition,was analyzed theoretically.
