Band Gap Energies of Solid Solutions in (CdTe)<SUB>1−<I>x</I></SUB>-(CdSe)<I><SUB>x</SUB></I> and (CdTe)<SUB>1−<I>x</I></SUB>-(CdS)<I><SUB>x</SUB></I> Systems

Abstract

Band gap energies of (CdTe)1−x-(CdSe)x and (CdTe)1−x-(CdS)x systems as a function of the composition were determined by diffuse reflectance measurement near the fundamental absorption edge for the micro-crystalline powder.The band gap energies of these systems deviate from a straight line interpolation of the band gap energies of the end components. In the compositionial range 0.4≤x≤0.55 for (CdTe)1−x-(CdSe)x system and x=0.225 for (CdTe)1−x-(CdS)x system, we got the samples with zinc blende or wurtzite structures for same composition. The band gap energies of these samples with wurtzite structure were higher than those of zinc blende structure by about 0.03∼0.06 eV.Bowing parameters calculated by the dielectric model proposed by Vechten were compared with the experimental values.