title: Increasing the band gap of iron pyrite by alloying with oxygen.
abstract: Systematic density functional theory studies and model analyses have been used to show that the band gap of iron pyrite (FeS(2)) can be increased from ~1.0 to 1.2-1.3 eV by replacing ~10% of the sulfur atoms with oxygen atoms (i.e., ~10% O(S) impurities). O(S) formation is exothermic, and the oxygen atoms tend to avoid O-O dimerization, which favors the structural stability of homogeneous FeS(2-x)O(x) alloys and frustrates phase separation into FeS(2) and iron oxides. With an ideal band gap, absence of O(S)-induced gap states, high optical absorptivity, and low electron effective mass, FeS(2-x)O(x) alloys are promising for the development of pyrite-based heterojunction solar cells that feature large photovoltages and high device efficiencies.
authors: Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA.
authors: Jun
authors: J
authors: Hu
authors: Yanning
authors: Y
authors: Zhang
authors: Matt
authors: M
authors: Law
authors: Ruqian
authors: R
authors: Wu