Microstructure of CuInS₂ films prepared by sulfuration of Cu–In–O films

Abstract

Polycrystalline CuInS₂ thin films are prepared by sulfuration of Cu–In–O films. The Cu–In–O films are deposited from a sintered Cu₂In₂O₅ target by using a pulsed laser deposition (PLD) method. Then, the Cu–In–O films are converted into CuInS₂ films by means of a subsequent annealing in an H₂S gas atmosphere. The characteristics of the films are determined by using an x-ray diffractometer (XRD), an energy dispersive x-ray spectrometer (EDX), and a scanning electron microscope (SEM). The effects of the deposition and sulfuration temperatures of the Cu–In–O films on the structural and microstructural properties of CuInS₂ films are examined experimentally. Single-phase CuInS₂ films with a chalcopyrite structure are obtained when Cu–In–O films are sulfurated at a temperature higher than 400 °C. Grain size of CuInS₂ is larger when a lower deposition temperature and a higher sulfuration temperature of Cu–In–O films are employed.