Solution-based synthesis and characterization of Cu_2FeSnS_4 nanocrystals

摘要

Cu_2FeSnS_4 nanocrystals were cost-effectively synthesized by thermal reactions of metal salts and sulfur in a hot oleylamine solution. Stannite structured Cu_2FeSnS_4 nanocrystals with diameters of about 15-25 nm were obtained, analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The morphology of the continuous Cu_2FeSnS_4 thin films was characterized by scanning electron microscopy (SEM) and the average compositions of the nanocrystals were determined by energy dispersive X-ray analysis (EDX). High-resolution X-ray photoemission spectroscopy (XPS) analysis of the four constituent elements indicated Cu (Ⅰ), Fe (Ⅱ), Sn (Ⅳ) and sulfide ions. The band gap of as-synthesised Cu_2FeSnS_4 nanocrystals is about 1.33 eV determined by the UV-vis-NIR absorption spectra measurement, which indicates its possible solar cell applications.