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Characterization of defect states in Ag0.5Cu0.5In5S8 solid solution by photoluminescence and thermally stimulated current

Photoluminescence (PL) and thermally stimulated current (TSC) in Ag(0.5)Cu(0.5)in(5)S(8) solid solution grown by Bridgman method have been studied in the photon energy region of 1.46-1.60 eV and in the temperature range of 10-42 K (PL) and in the temperature range of 10-100 K with heating rate of 1.01 K/s (TSC). A PL band centered at 1.53 eV was observed at T = 10 K. Variations of emission band has been studied as a function of excitation laser intensity in the 1.8-183.0 mW cm(-2) range. Radiative transitions from shallow donor level located at 13 meV below the bottom of conduction band to acceptor level located at 217 meV above the top of the valence band were suggesied to be responsible for the observed PL band. The analysis of the TSC data'revealed the electron trap level with activation energy 12 meV. An energy level diagram showing transitions in the band gap of the crystal has been presented.