Nanocrystalline Pyrite for Photovoltaic Applications

Transition metal sulfides (TMSs) are of special interest in energy conversion and storage devices. Amongst all sulfides, fool's gold or iron pyrite (FeS ₂) is potentially an attractive candidate for photovoltaic applications. Iron pyrite has risen to prominence due to its distinct properties and abundance in nature to meet the large scale needs. It is considered as environmentally benign solar absorber material with high absorption coefficient, α > 6 x10 ⁵ cm ⁻¹ for λ ≥ 700 nm and suitable energy bandgap (E _g=0.95 eV). Numerous physical and chemical methods have been employed to deposit nanocrystalline pyrite thin films directly from source materials or indirectly by sulfuration. This review gives an overview of pyrite as a low cost photovoltaic absorber material for contemporary solar cell structures. In addition, practical approaches like the rational design of nanocomposites, band gap engineering and nanostructure synthesis of pyrite for improving its properties particularly photovoltaic properties are also deliberated. Moreover, limitations, challenges, remedies and prospects of pyrite as potential photovoltaic material are also reviewed to further advance the development of pyrite-based solar cell configurations.