Effect of pH on the production of chalcopyrite CuInSe2 prepared by spray pyrolysis

Abstract

Thin films (∼1 μm) of CuInSe₂ were prepared by spray pyrolysis from solutions with various initial Cu:In:Se ratios and in which 75–90% of the acid was neutralized. The substrate temperature was varied between 225 and 300 °C. The chalcopyrite structure dominated the as‐sprayed films with 90% of the acid neutralized and 300 °C substrate temperature. At 225 °C all films were sphalerite independent of the degree of acid neutralization. Unlike previous studies which only produced the sphalerite structure in films prepared from unneutralized solutions, the present study indicates that the chalcopyrite phase can be produced in as‐sprayed films with a range of initial ratios.