Shape Control Iron Pyrite Synthesized by Hot Injection Method: Counter Electrode for Efficient Dye-Sensitized Solar Cells

The cubic and spherical shaped iron pyrite (FeS2) nanocrystals were synthesized in a pure phase form by an efficient hot injection method. These FeS2 nanocrystals were used as a counter electrode (CE) alternative to the conventional Pt CE in dye-sensitized solar cells (DSSCs) owing to its tremendous optical properties and low-cost. The obtained FeS2 nanocrystalline materials with excellent shape and phase purity were confirmed through XRD and Raman spectroscopy data. From Tafel, and impedance spectroscopy studies, the catalytic activity FeS2 CEs are found to be comparable with that of Pt CE. Along with the I-3(-)/I- electrolyte, photo-conversion efficiency is found to be 6.9% (spherical), 6.2% (cubic) for the FeS2 CE, and 7% for Pt CE. The excellent performance of the FeS2 CE in DSSCs makes it a distinctive choice among the various CE materials studied including low-cost photovoltaics. [GRAPHICS]