Microphotoluminescence study of Cu2ZnSnS4 polycrystals

Microphotoluminescence studies of Cu2ZnSnS4 polycrystals were performed. At room temperature, two photoluminescence (PL) bands were detected at 1.39 and 1.53 eV and attributed to band-to-tail (BT) and band-to-band (BB) recombination, respectively. At lower temperatures, band-to-impurity recombination always dominates. The results show that the model of heavily doped semiconductors applies to Cu2ZnSnS4 and that, in contrast to the ternary chalcopyrites, the BT recombination in Cu2ZnSnS4 has very low intensity. The laser power dependency of the PL intensity shows that the recombination mechanism of BT and BB bands exhibits an exciton-like behavior. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)