Effect of Different Selenium Precursors on Structural Characteristics and Chemical Composition of Cu2ZnSnSe4 Nanocrystals

Abstract

In this work, Cu2ZnSnSe4 nanocrystals were synthesized by the polyol method. The chemical composition and morphological, structural, and microstructural properties of Cu2ZnSnSe4 nanocrystals, depending on the synthesis temperature and time, as well as the composition of the precursor, have been thoroughly investigated using scanning and transmission electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, FTIR spectroscopy, Raman spectrometry, and low-temperature photoluminescence. We compared the properties of nanocrystals synthesized from different precursors containing selenourea or amorphous selenium as a source of selenium and then determined the optimal conditions for the synthesis of nanocrystals. It was found that the optimal synthesis time for nanocrystals obtained in the first approach is τ = 30–45 min, and in the second approach — τ = 120 min. It was also found that the optimal composition for the synthesis of single-phase Cu2ZnSnSe4 nanocrystals in the second approach is the molar ratio of precursors 2:1.5:1:4, and the synthesis temperature T = 280◦C. Thus, Cu2ZnSnSe4 nanocrystals synthesized under optimal conditions are used to develop nanoinks for printing solar cell absorbers by two- and three-dimensional printers.