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  Levcenko, S.; Guc, M.; Merschjann, C.; Gurieva, G.; Schorr, S.; Lux-Steiner, M.; Arushanov, E.: Photoluminescence characterization of Cu₂ZnGeS₄ single crystals. Physica Status Solidi C 10 (2013), p. 1079-1081

10.1002/pssc.201200843

Abstract:
Optical properties of the Cu2ZnGeS4 bulk single crystals were characterized by using Raman spectroscopy and photoluminescence spectroscopy technique. The strongest lattice vibration mode of this compound observed at 359 cm-1 and less intensive modes at 273, 291, 332, 370, 383, 405 and 414 cm-1. PL spectra of the Cu2ZnGeS4 consist of dominant broad emission band located at about 1.40 eV and a less intensive near 2.00 eV at 4.5 K. The observed PL bands were attributed to the donor acceptor pair transitions, with activation energy of 37 (140) meV for dominant and less intensive band, respectively.