Synthesis of Cu2ZnSnS4 monograin powders with different compositions

Abstract

The effect of changes in the composition ratios of Cu/(Zn+Sn) and Zn/Sn in initial precursor mixtures on the final composition and properties of Cu2ZnSnS4 (CZTS) monograin powders has been investigated. EDX studies revealed that Cu/(Zn+Sn) concentration ratios in the single phase powders can be changed only from 0.92 to 0.95 and Zn/Sn ratios only from 1.0 to 1.03. Raman spectra of all powders showed main peaks around 287, 338, and 375 cm-1 characteristic for CZTS materials. Larger deviations from stoichiometry results in CZTS powder crystals with secondary phases, identified as Sn2S3, SnS2, Cu2-xS and ZnS. All CZTS monograins have p-type conductivity with an electrical resistance in the range of 1.3 x103 to 1.6x104 Ω, depending on the initial composition of the precursor mixture.