Pressure effect on indirect excitons in ultra-thin GaAs/AlAs superlattices

Abstract

Photoluminescence spectra of a short-period superlattice composed of 20.4 AA GaAs and 14.7 AA AlAs layers are studied as a function of hydrostatic and uniaxial pressure at 80 K. It is found that the lowest excited state is an indirect exciton with a Gamma hole and an 'X'z electron. A 'camel's back' structure is needed to explain the time-decay data.