三元有序合金Ga_xIn_(1-x)P(x=0.52)的时间分辨谱  

Time-resolved photoluminescence spectra study of ordered Ga_(0.52)In_(0.48)P alloys

作　　者：高玉琳[1] 吕毅军[1] 郑健生[1] 蔡志岗[2] 桑海宇[2] 曾学然[2] 

机构地区：[1]厦门大学物理系,厦门361005 [2]中山大学超快速激光光谱学国家重点实验室,广州510275

出　　处：《物理学报》2002年第1期174-177,共4页Acta Physica Sinica

基　　金：国家自然科学基金 (项目编号 :697760 11);福建省自然科学基金资助的课~~

摘　　要：在室温和低温下 ,测试了有序Ga0 .52 In0 .4 8P的时间分辨光致发光谱 .对实验结果的分析表明 ,有序GaInP的发光呈双指数规律衰退 .室温下 ,快过程的时间常数在 12 8～ 2 5 0ps范围 ,低温 77K下则都有所变慢 ,大约在 186～ 5 64ps范围内 ;慢过程的时间常数根据不同样品有很大差异 ,室温下大约在 3 0 8～ 183 2ps之间变化 ,低温 77K下 ,则在纳秒量级 ,最长的甚至达到 2 8ns以上 .对两个过程的时间常数随激发功率密度变化的研究表明 ,快过程对应于有序区域中载流子的复合 ,慢过程则对应于有序区域和无序区域的空间分离中心上的载流子的复合 .低温下的时间分辨谱表明 。The time resolved photoluminescence (TRPL) spectra of ordered Ga 0.5 In 0.5 P alloys grown by metalorganic vapor phase epitaxy were investigated. The least\|square fitting of the luminescence decay spectra shows that there exist two exponential processes: for the quick process the lifetime τ 1 is about 128 ps—250 ps and 186 ps—546 ps at room temperature and 77 K, respectively; and for the slow process the lifetime τ 2 is, about 308 ps—1832 ps, at room temperature and at 77 K, as long as nanosecond and even more than 28ns. The short lifetime process belongs to the recombination of carriers in the ordered domains, corresponding to the high\|energy peak in the PL spectra. The long lifetime process corresponds to the low\|energy peak in the PL spectra. The strong excitation intensity dependence of τ 2 at a fixed energy indicates that the long lifetime process could not be explained in terms of donor\|acceptor pair(DAP). We attribute the emission to the recombination between the spatially separated centers of the electrons in ordered domains and the holes in disordered regions. The TRPL spectra at 77 K exhibit a blue\|shift with time delay, indicating that the carriers transfer from disordered regions to ordered domains.

关 键 词：时间分辨光致发光谱 Ⅲ-Ⅴ族半导体 三元有序合金 GaxIn1-xP 镓铟磷合金 

分 类 号：O472[理学—半导体物理]