Structural, Morphological and Charge Transport Properties of FeS2 Nanostructures

Iron disulfide (FeS2) has been synthesized using hydrothermal method. The spin coating method was employed for the deposition of FeS2 thin film on a glass substrate. Deposited films were characterized for their structural, morphological as well as carrier transport studies. X-ray diffraction and Raman analysis confirmed the formation of pyrite crystal structure, with excess elemental sulfur detected, leading to defect states in the crystal lattice. Field emission scanning electron microscopy (FESEM) results revealed that the deposited film possesses uniform morphology, with a thickness of approximately 40 nm, with particle size distribution similar to 10-55 nm. Temperature-dependent current-voltage measurements demonstrated a thermally activated conduction mechanism, with the current increasing linearly with temperature and an activation energy of 0.826 eV. This behaviour suggests thermal excitation of charge carriers across the bandgap as the primary mechanism for charge transport. The temperature-dependent electrical properties highlight the potential of FeS2 thin films for applications in gas sensing and photovoltaic devices.