Excitonic Absorption Spectra of GaAs–AlAs Superlattice at High Temperature

Abstract

Optical absorption spectra of MBE grown GaAs–AlAs superlattices with various thickness of the potential-well layer were measured in the temperature range up to 500 K. The excitonic absorption peak is observed even at a temperature of 500 K or higher. The broadening parameter \varGamma for the exciton peak was determined by a curve fitting. This parameter determines the temperature limit below which double absorption peaks due to heavy and light hole exciton are observed.