Data for Semiconductor-Quality Pyrite FeS₂ from Iron Ore

Pyrite FeS₂ is an approximately 1 eV bandgap semiconductor composed of exceptionally earth-abundant, low-cost, and non-toxic elements, with applications in numerous electronic and energy technologies. Facile and scalable synthesis of FeS₂ from natural resources is thus highly desirable, but must generate high-purity, semiconductor-quality material to access the widest range of applications. Here, we demonstrate that various forms of commercial iron ore, most notably taconite-based ore, can be used to synthesize semiconductor-quality FeS₂ via remarkably simple methods, despite very high initial impurity content. These ores can be reduced to Fe, sulfidized to FeS₂, then used in vapor-phase crystal growth to synthesize surprisingly high-quality FeS₂ with no additional purification. This is found to be possible due to two synergistic effects: very few elements efficiently dope FeS₂, and the sulfidation and crystal growth steps introduce significant unexpected purification, which we track via detailed trace element analyses. The result is pyrite single crystals with room-temperature Hall electron densities down to a remarkable 10¹⁶ cm⁻³, with corresponding mobilities exceeding 100 cm²V⁻¹s⁻¹. We thus demonstrate facile synthesis of semiconductor-quality FeS₂ from commercial iron ores, potentially unlocking a new renewable-energy revenue stream for an abundant natural resource.