三元合金Ga_(0.52)In_(0.48)P的时间分辨发光谱

在室温和低温液氮下 ,研究了有序和无序 Ga0 .52 In0 .4 8P的时间分辨发光谱。对实验结果的拟合表明 ,有序 Ga0 .52 In0 .4 8P的发光呈双指数规律衰退。其中快过程对应着有序区域上载流子的复合 ,慢过程则对应着有序区域和无序区域的空间分离中心上载流子的复合。无序 Ga0 .52 In0 .4 8P的发光在室温下呈单指数规律衰退。同时从低温下的时间分辨发光谱还可以看出有序样品的发光峰随着延迟时间的变长而蓝移 ,说明低温下在有序 Ga0 .52In0 .4 8P中存在着载流子从无序区域到有序区域的转移

Time-resolved PL Spectra Study of Ordered Ga0.52In0.48P Alloys

The time resolved photoluminescence(TRPL) spectra of ordered and disordered Ga 0.52 In 0.48 P alloys grown by MOVPE were investigated.The least square fitting of the luminescence decay spectra of ordered alloys shows that there exist two exponential processes:The short lifetime process was corresponding to the high energy peak in PL spectra which is attributed to the recombination of the carriers in the ordered domains and the long lifetime process was corresponding to the low energy peak in the PL spectra.The strong excitation intensity dependence of the long lifetime at fixed energy indicates that the long lifetime process could not be explained in terms of DAP.We attribute the emission to the recombination between the spatially separated locations of the electrons in ordered domains and the holes in disordered regions.For the disordered alloy of Ga 0.52 In 0.48 P, at room temperature and at 77K,the decay spectra can be fitted with single exponential.In addition,the TRPL spectra of ordered samples at 77K exhibit a blue shift with time delay,indicating that the carriers transfer from disordered regions to ordered domains.