Effect of Different S/In Ratio on Properties of In2S3 Films Prepared by Ultrasonic Spray Pyrolysis Method

In2S3 thin films have been prepared on heated glass substrates by ultrasonic spray pyrolysis method. Structure, surface morphology and properties of films with different S/In ratios have been investigated. XRD analysis demonstrated that as-prepared In2S3 thin films have a preferential orientation along the (220) direction and no other phases are observed. Uniformity, density, crystallinity of films were significantly affected by S/In ratios, which influence photoelectric properties of the films. In2S3 thin film is close to standard stoichiometric composition when S/In ratio is 2. Optical transmittance of films is over 90% in the visible region and its energy band gap come up to 2.46eV.