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 350 °C. Based on characterization 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.