Synthesis of CZTSe Nanocrystal Prepared by a Facile Route in Coordinating Solvent From Elemental Sources

Abstract

This paper reports the preparation of Cu2 ZnSnSe4 (CZTSe) nanocrystals from elemental sources through the application of various coordinating solvents. The CZTSe nanocrystals were synthesized by mixing metals in oleylamine (OLA) and isophorondiamine (IPDA) at a ratio of 1:3 as well as a Se solution in trioctylphosphine (TOP) under N2 flow at atmospheric pressure at a reaction temperature of 235 °C. X-ray diffraction and Raman spectroscopy were used to track the reaction mechanisms associated with various solvents. A growth mechanism, distinct from that associated with TOP/OLA, promoted the formation of nanoparticles and improved the reactivity provided by the addition of IPDA solvent through double N-chelation. The reaction mechanism involved in stannite Cu2 ZnSnSe4 phase crystallization from Cu2 SnSe3 and ZnSe is supported by theoretical analysis. The monodispersed CZTSe nanocrystals are polycrystalline and 20-30 nm in size. Optical measurements revealed a direct band gap of 1.42 eV. This study presents a relatively simple, low cost coordinating solvent route for the synthesis of CZTSe nanoparticles, applicable to the fabrication of low-cost thin-film solar cells.