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摘要: 采用有效质量模型和非线性弹性理论计算了不同尺寸InAs/GaAs量子点的静压光谱发光峰的 压力系数(PC).量子点峰位随压力的变化主要来自禁带宽度和电子束缚能随压力变化两方面 的贡献.由于InAs/GaAs量子点是一个应变体系，体系的晶格常数，失配应变和弹性系数均随 外加压力变化，使得加压后量子点的禁带宽度相对于非应变体系略有减小，同时势垒高度增 加，电子束缚程度增加.两者共同作用引起的InAs应变层的禁带宽度压力系数减小是导致量 子点的压力系数小于InAs体材料的主要原因.同时计算结果表明，电子束缚能随压力变化对 不同尺寸量子点的压力系数的影响不同，量子点尺寸越小，受其影响越大，压力系数也越大 .
Abstract: There is a significant diminution in the hydrostatic pressure coefficients (PCs) of the photoluminescence (PL) for InAs/GaAs quantum dots (QDs) in comparison wi th that of bulk binary. We study this phenomenon with the nonlinear elasticity t heory. The variation of the lattice and elastic constants plays an important rol e in the change of PCs, which causes the obvious decrease of the built-in strain s in InAs/GaAs QD. Therefore, the energy gap and the electronic confined energy change with pressure subsequently. It is the main reason for the measured small PCs of PL from QDs. Also the calculation reveals that the PCs are sensitive to t he sizes of QD. The smaller the quantum dot is, the more greatly the change of t he electronic confined energy affects the PCs. This effect gives rise to the inc rease of PCs when dot size is reduced.
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