Rapid thermal annealing effects on the optical properties in strained CdTe (100)/GaAs (100) heterostructures

The dependence of the optical properties on the annealing treatment for CdTe thin films grown on GaAs (100) substrates by using molecular beam epitaxy was investigated. Photoluminescence (PL) measurements were carried out to investigate the optical properties and to determine the activation energy of the confined electrons. The results show that the crystallinity of the CdTe/ GaAs heterostructure is improved by thermal treatment. It was found that the activation energies of the electrons existing at the donor state in the as-grown and the annealed heterostructures are 18 and 36 meV respectively.