Fabrication of semiconducting pyrite thin films from hydrothermally synthesized pyrite (FeS2) powder

Thin films of pyrite (FeS2) were fabricated using synthesized nano-particles and their structural, electrical and optical properties were characterized. Initially, pyrite-nano-particles were synthesized by an aqueous hydrothermal reaction. The X-ray diffraction confirmed that synthesized pyrite had a phase pure cubic pyrite structure with the average grain size around 30.0 nm. The pyrite films were fabricated by vacuum thermal evaporation of pyrite nanoparticles followed by a thermal sulfurization process. The as-deposited films have an amorphous structure and the sulfurized films have a cubic pyrite structure. The optical properties exhibited the bandgap closer to previously reported bandgap of pyrite. The photoconductivity of pyrite films was measured under AM1.5G sunlight and infrared (850 nm) light illumination. The photoconductivity data showed that the sulfurized pyrite films were more photoconductive than the as-deposited films.