Stress-induced anomalous shift of optical band gap in Ga-doped ZnO thin films: Experimental and first-principles study

Journal Article · Mon Apr 20 00:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4918933· OSTI ID:22398923

Wang, Yaqin; Tang, Wu; Liu, Jie ^[1]; Zhang, Lan ^[2]

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1. State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China)
2. State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049 (China)

In this work, highly c-axis oriented Ga-doped ZnO thin films have been deposited on glass substrates by RF magnetron sputtering under different sputtering times. The optical band gap is observed to shift linearly with the electron concentration and in-plane stress. The failure of fitting the shift of band gap as a function of electron concentration using the available theoretical models suggests the in-plane stress, instead of the electron concentration, be regarded as the dominant cause to this anomalous redshift of the optical band gap. And the mechanism of stress-dependent optical band gap is supported by the first-principles calculation based on density functional theory.

• OSTI ID: 22398923
• Journal Information: Applied Physics Letters, Vol. 106, Issue 16; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CONCENTRATION RATIO
DENSITY FUNCTIONAL METHOD
DOPED MATERIALS
ELECTRONS
ENERGY GAP
GALLIUM COMPOUNDS
GLASS
RED SHIFT
SPUTTERING
STRESSES
SUBSTRATES
THIN FILMS
ZINC OXIDES