摘要
用光调制反射谱(PR)测量了三块应变层 In_xGa_(1-x)As/GaAs 量子阱多重结构样品,每块样品中包含宽度为140、80、50、30和20A的量子阱.在300K和77K的PR谱中观察到各个量子阱的11H和11L光跃迁.根据PR数据用包络函数法进行分析,估算了量子阱中In的成分.在解释300K和77K实验结果时考虑了流体静压形变势常数的温度依赖性.实验和理论最佳符合时求得导带边不连续性在300K为0.7,77K为0.66.
Photoreflectance (PR) measurements have been performed on three strained-layerIn_xGa_(1-x) As/GaAs quantum-well (QW) multiple structure samples, each of which containsQWs of 140, 80, 50, 30 and 20A in widths. Optical transitions of 11H and 11L corresponding toeach of the QWs have been observed in the PR spectra at the temperatures of 300K and 77K. ThePR data have been analysed with the envelopefunction method, and the In compositions in theQWs have been estimated. The temperature dep endence of the hydrostatic deformation potentialconstant has been considered in the explanation of the PR data at 300K and 77K. The bestagreement between experiments and theoretical calculations is found with conduction band-offsets 0.7 at 300K and 0.66 at 77K.
