Optical characterization of bulk CuIn3Se5

The temperature dependence below liquid nitrogen of the photoluminescence a nd infrared absorption spectra at 300 K of bulk samples of CuIn3Se5 are rep orted. Intrinsic donor and acceptor levels at about 0.05 eV below the botto m of the conduction hand and 0.24 eV above the top of the valence band, res pectively, are obtained from the present optical data. A peak at 0.190 eV, consistent with earlier interpretation, is identified with the intervalence band transition due to the spin-orbit splitting. Also, deep localized stat es whose activation energies are around 0.40. 0.42. 0.46. 0.49 and 0.54 eV, probably having extrinsic origin, have also been observed from the optical absorption data. (C) 1999 Elsevier Science B.V. All rights reserved.