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扫描电镜阴极荧光技术不但有空间分辨的优点,也易于实现时间分辨。本文介绍延迟符合技术和利用该技术对砷化镓材料中缺陷荧光衰退过程的测量和分析。延迟符合技术原理示意于图一。以第一个光子事件为始脉冲、再设定一个终脉冲,其时间差由时间—幅度变换器检测,再转变为数字讯号存储在多道分析器(MCA)的相应道中。这样MCA中每一道的计数即代表在nΔt时刻,时间间隔Δt内光子发射的几率。这里n是道的序数,Δt是每一道的宽度。在适当的实验条件下,MCA输出的统计直方图就代表荧光衰弱的过程,由于采用(Sl阴极)光电倍增管探测及光子计数技术,有利于探测微弱讯号。
SEM fluorescence cathode fluorescent technology not only has the advantages of spatial resolution, but also easy to achieve time-resolved. This article describes the delay in line with the technology and the use of this technology for gallium arsenide material defects in fluorescence decay process measurement and analysis. Delay in line with technical principles shown in Figure I. With the first photon event as the start pulse, a final pulse is then set and the time difference is detected by the time-to-amplitude converter and converted to a digital signal that is stored in the corresponding channel of the MCA. In this way, the count of each track in the MCA represents the probability of photon emission within the time interval Δt at time nΔt. Where n is the ordinal number of the road, and Δt is the width of each lane. Under appropriate experimental conditions, the statistical histogram output from the MCA represents the process of decay of fluorescence. It is advantageous to detect weak signals due to (Sl cathode) photomultiplier tube detection and photon counting.