Growth of AgInS2 thin films by ultrasonic spray pyrolysis technique

Silver Indium Di-sulfide (AgInS2) thin films are deposited using ultrasonic spray pyrolysis technique and the effect of substrate temperature (Ts) on film growth is studied by varying the temperature from 250 to 400 °C. From the structural analysis, orthorhombic AgInS2 phase is identified with preferential orientation along (002) plane. Further analysis with Raman revealed the coexistence of Cu-Au ordered and chalcopyrite structures in the films. Stoichiometric films are obtained at Ts of 300 °C. Above 300 °C, the film conductivity changed from p to n-type and the grain size decreased. The band gap of AgInS2 films varied from 1.55 to 1.89 eV and absorption coefficient is found to be > 104 cm− 1. The films have sheet resistance in the range of 0.05 to 1300 Ω/□. Both p and n type films are prepared through this technique without any external doping.