Direct band gap energies and energy levels of Co 2+ ion in ternary compound semiconductors by photoacoustic technique

Abstract

Photoacoustic spectra of CdGa 2Se 4, ZnGa 2Se 4 and MgGa 2Se 4 semiconductors have been measured to obtain the optical fundamental band gap energies and the allowed interband transition energies of these materials. The samples of doped with Co in the above three semiconductors have been also investigated to see the energy levels of Co 2+ ions which are located at S 4 symmetry sites for CdGa 2Se 4 and at Td symmetry sites for both ZnGa 2Se 4 and MgGa 2Se 4.