Annealing and light effect on optical and electrical properties of evaporated indium selenide thin films

Indium selenide thin films have been deposited by vacuum evaporation method on glass substrates at a vacuum level of 10−5 Torr. The annealing temperature effect on optical band gap and the light effect on the electrical properties of films have been investigated. Scanning electron microscopy and X-ray diffraction techniques were used for the investigation of structural properties of films. Optical band gap values of films have been changed from 1.33 to 2.08 eV with annealing temperature due to the formation of γ-In2Se3 phase. The light effect on electrical properties has been investigated and it was found that the current increase with increasing light intensity and increasing rate in illuminated 500 W film was greater than in others. There is a very important decreasing in the resistance values of the samples that are annealed at 300 and 400 °C because of the improvement of the crystallization.