Structural, electronic structure, and band alignment properties at epitaxial NiO/Al{sub 2}O{sub 3} heterojunction evaluated from synchrotron based X-ray techniques

Journal Article · Thu Apr 28 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4947500· OSTI ID:22594658

Das, Arijeet; Ajimsha, R. S.; Upadhyay, Anuj; Kamparath, Rajiv; Mukherjee, C.; Misra, P.; Rai, S. K.; Sinha, A. K.; Ganguli, Tapas ^[1]; Nand, Mangla; Jha, S. N. ^[2]; Shukla, D. K.; Phase, D. M. ^[3]

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1. Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh 452013 (India)
2. Bhabha Atomic Research Centre, Mumbai, Maharashtra 400085 (India)
3. UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore, Madhya Pradesh 452017 (India)

The valence band offset value of 2.3 ± 0.2 eV at epitaxial NiO/Al{sub 2}O{sub 3} heterojunction is determined from photoelectron spectroscopy experiments. Pulsed laser deposited thin film of NiO on Al{sub 2}O{sub 3} substrate is epitaxially grown along [111] direction with two domain structures, which are in-plane rotated by 60° with respect to each other. Observation of Pendellosung oscillations around Bragg peak confirms high interfacial and crystalline quality of NiO layer deposited on Al{sub 2}O{sub 3} substrate. Surface related feature in Ni 2p{sub 3/2} core level spectra along with oxygen K-edge soft X-ray absorption spectroscopy results indicates that the initial growth of NiO on Al{sub 2}O{sub 3} substrate is in the form of islands, which merge to form NiO layer for the larger coverage. The value of conduction band offset is also evaluated from the measured values of band gaps of NiO and Al{sub 2}O{sub 3} layers. A type-I band alignment at NiO and Al{sub 2}O{sub 3} heterojunction is also obtained. The determined values of band offsets can be useful in heterojunction based light emitting devices.

• OSTI ID: 22594658
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 16; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
ABSORPTION SPECTROSCOPY
ALUMINIUM OXIDES
BRAGG CURVE
DEPOSITS
DOMAIN STRUCTURE
ELECTRONIC STRUCTURE
ENERGY BEAM DEPOSITION
EPITAXY
HETEROJUNCTIONS
LASERS
LAYERS
NICKEL OXIDES
PHOTOELECTRON SPECTROSCOPY
SOFT X RADIATION
SPECTRA
SUBSTRATES
SYNCHROTRONS
THIN FILMS
X-RAY SPECTROSCOPY