X-ray diffraction and compositional studies of AgInS2 thin films obtained by spray pyrolysis

Abstract

Silver indium sulfide (AgInS2) thin films have been prepared by the spray pyrolysis technique using silver acetate, indium acetate, and N,N-dimethylthiourea as pre- cursor compounds. Depending on the film preparation conditions, AgInS2 thin films are obtained which could be candidates to be used in photovoltaic devices. X-ray dif- fraction (XRD) and energy dispersive spectroscopy (EDS) compositional studies were done on films formed at dif- ferent substrate temperatures (Ts) and Ag:In:S ratios in the starting solutions. When Ag:In:S ratios are 1:1:1, 1:0.25:2, and 1:1:2, XRD patterns of the thin films indicated that the crystallographic structure is mainly chalcopyrite AgInS2. An additional phase, acanthite Ag2S, appeared when the depositions where done at low Ts. EDS analysis showed that AgInS2 films near stoichiometric composition were obtained by using an atomic ratio of Ag:In:S = 1:1:2 in the starting solution and Ts = 400 C.