Eco-friendly synthesis of SnSe nanoparticles: effect of reducing agents on the reactivity of a Se-precursor and phase formation of SnSe NPs

Abstract

Tin monoselenide (SnSe) nanoparticles (NPs) have great potential to replace the conventional absorbers used in the fabrication of thin film solar cells. However, studies pertaining to the synthesis and fabrication of SnSe NPs-based solar cells are still lacking. This study presents an eco-friendly synthesis of SnSe NPs by a chemical precipitation method in a short reaction time of 10 min. The effect of different reducing agents (such as NaOH, ethylenediamine, Na₂SO₃, and NaBH₄) on the reactivity of a Se-precursor and phase formation of SnSe NPs was investigated in detail. Our study indicated that the reaction between Sn²⁺ ions complexed by ascorbic acid and Se²⁻ ions provided by the reduction with NaBH₄ resulted in the formation of single phase SnSe NPs. For the first time, a SnSe NPs thin film inorganic solar cell with the device structure of SLG/Mo/SnSe NPs/CdS/i-ZnO/Al:ZnO/Ni/Ag was fabricated and tested, which showed an efficiency of 0.43%.