title: Electron transport in pure and doped hematite.
abstract: Hematite (α-Fe(2)O(3)) is a promising candidate for photoelectrochemical splitting of water. However, its intrinsically poor conductivity is a major drawback. Doping hematite to make it either p-type or n-type enhances its measured conductivity. We use quantum mechanics to understand how titanium, zirconium, silicon, or germanium n-type doping affects the electron transport mechanism in hematite. Our results suggest that zirconium, silicon, or germanium doping is superior to titanium doping because the former dopants do not act as electron trapping sites due to the higher instability of Zr(III) compared to Ti(III) and the more covalent interactions between silicon (germanium) and oxygen. This suggests that use of n-type dopants that easily ionize completely or promote covalent bonds to oxygen can provide more charge carriers while not inhibiting transport.
authors.affiliation: Department of Chemistry, Princeton University, Princeton, New Jersey 08544-5263, United States.
authors.forename: Peilin
authors.initials: P
authors.lastname: Liao
authors.forename: Maytal Caspary
authors.initials: MC
authors.lastname: Toroker
authors.forename: Emily A
authors.initials: EA
authors.lastname: Carter
mesh_terms: D003198:Computer Simulation; D004579:Electron Transport; D005290:Ferric Compounds / Q000737:chemistry*; D008956:Models, Chemical; D011789:Quantum Theory
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide