In_xGa_（1－x）As／Al_yGa（1－y）As多量子阱的高压光致发光研究

PHOTOLUMINESCENCE STUDIES OF In_xGa_(1-x)As/Al_yGa_(1-y)As MULTIPLE QUANTUM WELLS UNDER HIGH PRESSURE

用金刚石对顶砧压力装置在液氮温度下和０～４ＧＰａ的压力范围内测量了不同阱宽（１．７～１１．０ｎｍ）的ＩｎｘＧａ（１－ｘ）Ａｓ／Ａｌ（１－ｙ）Ｇａ（１－ｙ）Ａｓ（ｘ，ｙ＝０．１５，０；０．１５，０．３３；０，０．３３）多量子阱的静压光致发光谱，发现在Ｉｎ０．１５Ｇａ０．８５Ａｓ／ＧａＡｓ多量子阱中导带第一子带到重空穴第一子带间激子跃迁产生的光致发光峰能量的压力系数随阱宽的增加而减小，在Ｉｎ０．１５Ｇａ０．８５Ａｓ／Ａｌ０．３３Ｇａ０．６７Ａｓ和ＧａＡｓ／Ａｌ０．３３Ｇａ０．６７Ａｓ多量子阱中相应发光峰的压力系数随附宽的增加而增加．根据Ｋｒｏｎｉｙ－Ｐｅｎｎｅｙ模型计算了发光峰能量的压力系数随阱宽的变化关系，结果表明导带不连续性随压力的增加（减小）及电子有效质量随压力的增加是压力系数随阱宽增加而减小（增加）的主要原因．

Using diamond anvil cells, the photoluminescence (PL) spectra of InxGa(1-x)As/AluGa(1-y).As (x, y = 0.15, 0; 0.15, 0.33; 0, 0.33) multiple quantum wells (MoWs) with well widths from 1.7 to 11.0nm were measured at 77K under highpressure up to 4GPa. The experimental results show that the pressure coefficients of the exciton peaks corresponding to transitions from the first conduction subband to the heavy-hole subband decrease with increasing wen width for in0.15Ga0.85As/GaAs MoWs. However, the corresponding pressure coefficients increase for In0.15Ga0.85As/Al0.33Ga0.67As and GaAs/Af0.33Ga0.67As MQWs, respectively. Calculations based on the Kroulg-Penney model reveal that the increased or decreased conductionfoand offsets and the increased effective masses of electrons with increasing pressure are the maill reasons of the change in the pressure coefficiellts.