Preparation and characterization of layer-diffusion processed InBi2Se4 thin films for photovoltaics application

In this research work, optoelectronic properties of Indium bismuth selenide (InBi2Se4) thin films are studied for their potentials for photovoltaic applications. The InBi2Se4 films are prepared via a thermal co-evaporation technique on glass substrate using Bi2S3 powders and indium granules. The as-deposited films are then annealed at different temperatures to convert into InBi2Se4 thin films. Results show that the obtained InBi2Se4 films possess excellent optoelectronic properties as an optimum bandgap of 1.2 eV was obtained for the film annealed at 350oC. Based on characterisation results of current and voltage realiationships, both as-deposited and annealed InBi2Se4 thin films show a linear relationship between current and annealing temperature. It was also noted that with increasing grain-size of the film, the current is also increased at a fixed applied voltage.