Direct type II–indirect type I conversion of InP/GaAs/InP strained quantum wells induced by hydrostatic pressure

Abstract
Photoluminescence from thin strained layers of GaAs grown on InP has been studied under hydrostatic pressure. The structures are type II at atmospheric pressure. At higher pressures the structures change to type I with the lowest conduction band edge in the strained GaAs layer being the X minimum. This transformation is characterized by a drastic change in the pressure derivative of the emission energy and a rapid disappearance of the photoluminescence intensity at slightly higher pressures. A hydrostatic pressure derivative of less than one meV/kbar is measured for the valence band offset.