Effect of substrate temperature on properties of thin films prepared by RF sputtering from CuInSe 2 target with Na 2Se

Abstract

We fabricated the thin films by RF sputtering from Na-mixed CuInSe 2 target, and investigated the effect of the substrate temperature on the formation of CuIn 3Se 5 thin films. From electron probe microanalysis (EPMA) measurements, the copper content was found to decrease with increasing the substrate temperature, and the band gap of the thin films became large, suggesting the formation of CuIn 3Se 5 structure. The reduction of copper content was presumed to be due to the surface reaction during the growth. Based on the results, one of the growth models for CuIn 3Se 5 is proposed.