Double-hole-induced oxygen dimerization in transition metal oxides
- Author(s): Chen, S
- Wang, LW
- et al.
Published Web Locationhttps://doi.org/10.1103/PhysRevB.89.014109
Rather than being free carriers or separated single-hole polarons, double holes in anatase TiO prefer binding with each other, to form an O-O dimer after large structural distortion. This pushes the hole states upward into the conduction band and traps the holes. Similar double-hole-induced O-O dimerization (a bipolaron) exists also in other transition metal oxides (TMOs) such as V O5 and MoO , which have the highest valence bands composed mainly of O 2p states, loose lattices, and short O-O distances. Since the dimerization can happen in impurity-free TMO lattices, independent of any extrinsic dopant, it acts as an intrinsic and general limit to the p-type conductivity in these TMOs. © 2014 American Physical Society. 2 2 3