A study on the synthesis of iron pyrite thin films for use as a photovoltaic absorber

Although iron pyrite had been identified as a novel photo-voltaic material, it is yet to be harnessed. Iron pyrite forms mechanically unstable films with pinholes. A simple method has been devised to greatly improve the mechanical stability of iron pyrite thin films grown on quartz. This is done by annealing the precursor films prior to sulfurizing in vacuum-sealed quartz tubes. It has also been shown that an equilibrium based process is necessary to synthesize films of good quality. Zinc was successfully incorporated into iron pyrite thin films to increase the bandgap by 0.1 eV. The electronic properties of these films are similar to that found in literature. It has been identified that cracks in the film and voids between the grains are the cause for poor electronic properties. Composition analysis showed a high degree of oxygen contamination in iron precursor films resulting in poor electronic properties of iron pyrite films obtained by sulfuring the precursor films. Thus it may be possible to synthesize high quality films if these issues are addressed.