Determination of carrier lifetime in thermally evaporated In2S3 thin films by light induced transient grating technique

In2S3 thin films were deposited onto soda lime glass substrates using thermal evaporation technique at a constant substrate temperature of 300 °C and the films were annealed in a sulfur ambient at 250 °C and 300 °C for 1 h. Light induced transient grating (LITG) technique was used to determine the carrier lifetime in In2S3 thin films. The determined carrier lifetime values for different excitation energy densities, I0 = 0.06–1.64 mJ/cm2 decreased from 206  to 18 ps and 150 to 14 ps for the films annealed at 250 °C and 300 °C respectively. Further, the bimolecular, Auger recombination coefficients and diffusion coefficient were determined in the films. The observed bimolecular carrier recombination origin was explained by interface and Auger recombination processes.