Solvothermal Synthesis of CuInS2 Nanoparticles in Ethylene Glycol–Water Medium and Their Photovoltaic Properties

Abstract

CuInS2 nanoparticles were synthesized by a solvothermal method using a 1:1 (v/v) water : ethylene glycol (EG) as a binary solvent mixture. The synthesized powder, characterized by XRD technique, was indexed as CuInS2 with a tetragonal structure. FESEM and TEM images revealed that the CuInS2 powder composed of spherical nanoparticles with diameters in the range of 15–30 nm. The CuInS2 powder was also synthesized using water as a solvent for comparison. Particle size of the CuInS2 nanoparticles synthesized using mixed solvent of water : EG was smaller with softer agglomeration behavior than those synthesized using water (50–75 nm) offering better photovoltaic properties, including open-circuit voltage (Voc), short-circuit current density (Jsc), and conversion efficiency (η). The difference in these characteristics of the CuInS2 nanoparticles was discussed based on some physicochemical properties of the solvents used.