Hydrostatic Pressure Study of GaAs- Al(x)Ga(l-x)As Quantum Wells at Low Temperatures

摘要

It has recently been demonstrated that the valence band (VB) offset delta E sub V can be determined from accurate photoluminescence (PL) measurements on type II superlattices (SL). By the application of hydrostatic pressure, the Gallium Arsenide-Al(x)Ga(1-x)As quantum well system, which is normally a type I SL, can be transformed into a type II SL. In this paper, we focus on the determination of Delta E sub V and how it changes with pressure. The well width dependence of the pressure coefficients (alpha) will also be discussed. We have studied PL from a SL with 40 periods of 150 GaAs wells separated by 100 Al(0.25)Ga(0.75)As barriers grown on a GaAs substrate by molecular beam epitaxy (MBE). Hydrostatic pressure measurements were done in a gasketed diamond anvil cell with argon as the pressure medium and ruby R-line fluorescence as the manometers.