Synthesis of single-phase material Cu2ZnSnSe4 in a melt of alkali metal salts

Abstract

In this work, CZTSe was synthesized by direct fusion of chemical elements in a quartz
ampoule. XRD method was ineffective for evaluating the single-phase nature of the product, due to overlapping
characteristic CZTSe peaks with peaks of secondary phases. While Raman spectroscopy revealed the presence
of phases like Cu2SnSe3, ZnSe and SnSe in the sample. By recrystallization in a melt-solution of alkali metal salts
at a temperature of 750° C, a single-phase product was obtained. As a solvent, a KI-KCl eutectic mixture was
selected. According to the results of Raman spectroscopy and SEM, it was shown that after recrystallization in a
melt-solution for 14 hours, single-phase and homogeneous composition of CZTSe is achieved.