用Laplace谱研究缺陷深能级精细结构

Study of Deep-level Fine Structure by Laplace Defect Spectroscopy

用Laplace缺陷谱仪 (LDS)实验研究了GaAsP中Fe深受主上空穴发射和AlGaAs中SnDX中心上电子发射引起的非指数瞬态 ,发现它们起因于混晶无序效应。与DLTS的单一谱峰比较 ,LDS谱呈现出多峰结构。由深能级上空穴与电子热发射率随温度关系的直线拟合 ,得到多峰结构各峰谱的激活能 ,认为它们反映杂质深中心与其近邻原子的不同结构。研究表明 ,LDS适用于深能级精细结构的研究。

A Laplace defect spectrometer (LDS) is applied to study non exponential transients resulting from hole emission from Fe related deep acceptors in GaAsP and electron emission from Sn related DX centers in AlGaAs. The non exponential transients which bear a relationship to the alloy random effect are investigated under different conditions. Their LDS spectra exhibit several well resolved sharp peaks assigned to the fine structures of the Fe related deep acceptors and the two DX centers, respectively. The activation energies of the fine structures are determined by linear fitting of the slopes of temperature dependences of hole and electron emission rates. The results show that the LDS is useful for investigation of deep level fine structures.