Abstract
Hematite (α-Fe2O3) 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.
Original language | English (US) |
---|---|
Pages (from-to) | 1775-1781 |
Number of pages | 7 |
Journal | Nano Letters |
Volume | 11 |
Issue number | 4 |
DOIs | |
State | Published - Apr 13 2011 |
All Science Journal Classification (ASJC) codes
- General Chemistry
- Condensed Matter Physics
- Mechanical Engineering
- Bioengineering
- General Materials Science
Keywords
- Iron oxides
- electron transport
- n-type doping