Novel route to prepare iron sulphide as a counter electrode for dye-sensitized solar cell

In this study, iron sulphide thin films were prepared by simple and low-cost chemical spray-pyrolysis method using tilt deposition with a spraying angle of 45° and substrates temperature of 200°C. The precursors were iron chloride salt (FeCl3) and thiourea. After the preparation process, some of the samples are annealed at a temperature 400°C for 30 min. It was found that the as-deposited iron sulphide thin films (without annealing) had an amorphous structure, which gave higher absorption coefficient (2 × 105 cm−1) for thin film thickness 400 nm. This study also presents a novel method to obtain polycrystalline FeS2 thin films with pyrite phase and optimum energy bandgap and high absorption coefficient. A thin film of iron sulphide was also deposited on fluorine-doped tin oxide glass to work as a counter electrode for dye-sensitized solar cells.