Growth of AgInS_2 thin films by ultrasonic spray pyrolysis technique

摘要

Silver Indium Di-sulfide (AgInS_2) thin films are deposited using ultrasonic spray pyrolysis technique and the effect of substrate temperature (T_s) on film growth is studied by varying the temperature from 250 to 400 ℃. From the structural analysis, orthorhombic AgInS_2 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 T_s of 300 ℃. Above 300 ℃, the film conductivity changed from p to n-type and the grain size decreased. The band gap of AgInS_2 films varied from 1.55 to 1.89eV and absorption coefficient is found to be ＞ 10~4 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.