Shallow defects in Cu2ZnSnS4

摘要: Cu 2 SnZnS 4 is a promising candidate for thin film solar cells with absorbers made of non-toxic and abundant elements. So far very little effort has been put into understanding the basic material properties. We investigate vapour phase grown crystals by temperature intensity dependent photoluminescence measurements. observe first time narrow peaks, which allow us to determine defect levels propose recombination model . Assuming an exciton binding energy 10 meV, we find gap 1.519 eV at K. From observed DA transitions derive energies two shallow acceptor states 10±5 30+5 meV above valence band one donor state 5±3 below conduction band.