Effect of Mg doping on the structural and free-charge carrier properties of InN films

Journal Article · Mon Apr 28 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4871975· OSTI ID:22273536

Xie, M. -Y.; Ben Sedrine, N.; Hung, L.; Monemar, B.; Schöche, S.; Hofmann, T.; Schubert, M. ^[1]; Wang, X. ^[2]; Yoshikawa, A. ^[3]; Wang, K.; Araki, T. ^[4]; Nanishi, Y. ^[4]

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1. Center for Nanohybrid Functional Materials, Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States)
2. State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing (China)
3. Center for SMART Green Innovation Research, Chiba University, Chiba (Japan)
4. Department of Photonics, Ritsumeikan University, 1-1-1 Noji Higashi, Kusatsu, Shiga 525-8577 (Japan)

We present a comprehensive study of free-charge carrier and structural properties of two sets of InN films grown by molecular beam epitaxy and systematically doped with Mg from 1.0 × 10{sup 18} cm{sup −3} to 3.9 × 10{sup 21} cm{sup −3}. The free electron and hole concentration, mobility, and plasmon broadening parameters are determined by infrared spectroscopic ellipsometry. The lattice parameters, microstructure, and surface morphology are determined by high-resolution X-ray diffraction and atomic force microscopy. Consistent results on the free-charge carrier type are found in the two sets of InN films and it is inferred that p-type conductivity could be achieved for 1.0 × 10{sup 18} cm{sup −3} ≲ [Mg] ≲ 9.0 × 10{sup 19} cm{sup −3}. The systematic change of free-charge carrier properties with Mg concentration is discussed in relation to the evolution of extended defect density and growth mode. A comparison between the structural characteristics and free electron concentrations in the films provides insights in the role of extended and point defects for the n-type conductivity in InN. It further allows to suggest pathways for achieving compensated InN material with relatively high electron mobility and low defect densities. The critical values of Mg concentration for which polarity inversion and formation of zinc-blende InN occurred are determined. Finally, the effect of Mg doping on the lattice parameters is established and different contributions to the strain in the films are discussed.

• OSTI ID: 22273536
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMIC FORCE MICROSCOPY
CHARGE CARRIERS
COMPARATIVE EVALUATIONS
CONCENTRATION RATIO
CUBIC LATTICES
DOPED MATERIALS
ELECTRON MOBILITY
ELECTRONS
ELLIPSOMETRY
HOLES
INDIUM NITRIDES
LATTICE PARAMETERS
MICROSTRUCTURE
MOLECULAR BEAM EPITAXY
MORPHOLOGY
POINT DEFECTS
STRAINS
THIN FILMS
X-RAY DIFFRACTION