Phase-pure iron pyrite nanocrystals for low-cost photodetectors

Earth-abundant iron pyrite (FeS(2)) shows great potential as a light absorber for solar cells and photodetectors due to their high absorption coefficient (>10(5) cm(-1)). In this paper, high-quality phase-pure and single crystalline pyrite nanocrystals were synthesized via facile, low-cost, and environment friendly hydrothermal method. The molar ratio of sulphur to iron and the reaction time play a crucial role in determining the quality and morphology of FeS(2) nanocrystals. X-ray diffraction and high-resolution transmission electron microscopy confirm that phase-pure and single crystalline pyrite nanocrystals can be synthesized with high sulphur to iron molar ratio and sufficient reaction time. For the first time, a crystalline nanogap pyrite photodetector with promising photocurrent and UV-visible photoresponse has been fabricated. This work further demonstrates a facile route to synthesize high-quality FeS(2) nanomaterials and their potential in optoelectronic applications.