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Title: Spontaneous polarization driven Mg concentration profile reconstruction in MgZnO/ZnO heterostructures

Atomic reconstruction at the interface of MgZnO and ZnO in molecular beam epitaxy grown heterostructures is investigated. Using secondary ion mass spectroscopy, we experimentally find that Mg atomic reconstruction depends on the polarity of the interface; it is not observed in n-type interfaces (MgZnO on Zn-polar ZnO) owing to electron accumulation, while in p-type interfaces (ZnO on Zn-polar MgZnO), Mg drastically redistributes into the ZnO layer. Combined with self-consistent calculation of band profiles and carrier distributions, we reveal that the observed Mg reconstruction is not due to thermal diffusion but consequences in order to avoid hole accumulation. This tendency implies inherent significant asymmetry of energy scales of atomic and electronic reconstructions between n-type and p-type interfaces.
Authors:
; ; ;  [1] ;  [2] ;  [3]
  1. Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo 113-8656 (Japan)
  2. Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)
  3. (JST), Chiyoda-ku, Tokyo 102-0075 (Japan)
Publication Date:
OSTI Identifier:
22300303
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ASYMMETRY; CARRIERS; ELECTRONS; HOLES; INTERFACES; ION MICROPROBE ANALYSIS; LAYERS; MAGNESIUM COMPOUNDS; MASS SPECTROSCOPY; MOLECULAR BEAM EPITAXY; POLARIZATION; SPATIAL DISTRIBUTION; THERMAL DIFFUSION; ZINC OXIDES