Control of the band-gap states of metal oxides by the application of epitaxial strain: The case of indium oxide

Journal article

We demonstrate that metal oxides exhibit the same relationship between lattice strain and electronic band gap as nonpolar semiconductors. Epitaxial growth of ultrathin [111]-oriented single-crystal indium-oxide films on a mismatched Y-stabilized zirconia substrate reveals a net band-gap decrease, which is dissipated as the film thickness is increased and the epitaxial strain is relieved. Calculation of the band-gap deformation of In2O 3, using a hybrid density functional, confirms that, while the uniaxial lattice contraction along [111] results in a band-gap increase due to a raise of the conduction band, the lattice expansion in the (111) plane caused by the substrate mismatch compensates, resulting in a net band-gap decrease. These results have direct implications for tuning the band gaps and transport properties of oxides for application in optoelectronic devices. © 2011 American Physical Society.

Authors: Walsh, A; Catlow, C; Zhang, K; Egdell, R

• Publication status: Published
• Journal: Physical Review B
• Volume: 83
• Issue: 16
• Publication date: 2011-04-12
• DOI: 10.1103/PhysRevB.83.161202
• EISSN: 1550-235X
• ISSN: 1098-0121
• Language: English