Photoactive Synthetic Polycrystalline Pyrite ( FeS2 )

Polycrystalline layers of As‐doped pyrite have been produced in bromine atmosphere with the aim of developing this sulfide material for solar energy applications. Its photoelectrochemical behavior in contact with an aqueous electrolyte was investigated. It operated as a photoelectrochemical solar cell and showed reasonably stable behavior under illumination. Optical measurements performed on show that visible light is absorbed in an extremely thin layer of 160Å in spite of the apparently indirect gap of this semiconductor . This would make this photosensitive material an interesting candidate for thin‐layer solar cells. Scanning electron micrographs of the samples reveal well‐developed crystallites of about 5–10 μm with distinct boundaries. Scanning laser spot analysis over macroscopic areas (5 mm) showed homogeneous as well as inhomogeneous regions. The photoelectric properties of these first polycrystalline pyrite samples studied are poor, but there is presently no reason to assume that they cannot be developed.