Correlation of ZnO orientation to band alignment in p-Mg0.2Ni0.8O/n-ZnO interfaces.

Authors :: Zhou, T. T.
Lu, B.
Wu, C. J.
Ye, Z. Z.
Lu, J. G.
Pan, X. H.
Source :: Journal of Applied Physics; Oct2013, Vol. 114 Issue 14, p143707, 5p, 1 Diagram, 1 Chart, 4 Graphs
Publication Year :: 2013
Abstract: We have investigated the influence of ZnO orientation on the valence band offset (ΔE<subscript>V</subscript>) of Mg0.2Ni0.8O(111)/ZnO (11<OVERLINE>2</OVERLINE>0) and Mg0.2Ni0.8O(111)/ZnO(0002) heterostructures by x-ray photoelectron spectroscopy. Combining with the experimental optical energy band gap extracted from UV-vis transmittance spectra, the energy band alignment at the interfaces has been determined. The ΔE<subscript>V</subscript> has been found to be 1.8 ± 0.1 eV and 1.4 ± 0.1 eV for Mg0.2Ni0.8O(111)/ZnO (11<OVERLINE>2</OVERLINE>0) and Mg0.2Ni0.8O(111)/ZnO(0002), respectively. Both the heterostructures show type-II band configurations with conduction band offsets (ΔE<subscript>C</subscript>) of 2.4 ± 0.1 eV and 2.0 ± 0.1 eV, respectively. The ZnO orientation correlated electronic structure in p-Mg0.2Ni0.8O/n-ZnO interfaces can be explained well by the effect of spontaneous polarization in ZnO. Furthermore, the results offer opportunity that desired band offsets in MgxNi1-xO/ZnO heterostructures can be obtained by appropriately adjusting Mg composition. [ABSTRACT FROM AUTHOR]

Subjects :: ZINC oxide
VALENCE bands
HETEROJUNCTIONS
HETEROSTRUCTURES
X-ray photoelectron spectroscopy

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