光电容法研究电子辐照GaP中的深能级

本文提出含多个深能级响应的光电容瞬态分析方法:在不考虑各能级之间电子、空穴跃迁的条件下,可出“多指数过程分离法”,将总的瞬态过程分离为各能级上指数型瞬态过程之和.运用这一方法,对lMeV(4×1015cm-2电子辐照GaP LED进行了定态和两种注入条件的瞬态光电容测量,观察到H1、H2、H3三个空穴能级(0.51、0.75、1.15eV)和E1、E2、E3、E4四个电予能级(0.68、0.84、0.89、1.01eV),并得到各能级的光离化截面谱.外量子效率及发射谱测量结果表明;电子辐照引入的深能级(H1-H3,E1-E4)表现出无辐射复合中心的性质.

STUDIES ON DEEP LEVELS IN ELECTRON-IRRADIATED GaP BY PHOTOCAPACITANCE METHOD

In this paper, a method is suggested to analyze the photocapacitance transient which may relate to several deep levels, and the photoionization cross sections, energy positions and concentration of deep levels in 1MeV electron-irradiated GaP :N LED have been measured by photocapacitance technique. And the roles of these deep levels in electron-hole recombination are specified.Photocapacitance experiments showed that certain deep levels in GaP are resulted from electron-irradiation, and that the photocapacitance transient which may include a number of electron or hole emissions from these deep levels is almost always non-exponential. If the electron and hole transitions between deep levels may be neglected, the total transient can be expressed as the sum of the exponential transients corresponding to the deep levels from which electrons or holes are excited to conduction/valence band by light.