Band gap bowing parameter in pseudomorphic Al{sub x}Ga{sub 1−x}N/GaN high electron mobility transistor structures

Journal Article · Sun Jun 14 04:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4922286· OSTI ID:22412938

Goyal, Anshu; Kapoor, Ashok K.; Raman, R.; Dalal, Sandeep; Mohan, Premila; Muralidharan, R. ^[1]

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1. Solid State Physics Laboratory, Lucknow Road, Delhi 110054 (India)

A method for evaluation of aluminium composition in pseudomorphic Al{sub x}Ga{sub 1−x}N layer from the measured photoluminescence (PL) peak energy is presented here. The layers were grown by metalorganic chemical vapor deposition and characterized by high resolution X-ray diffraction (HRXRD), PL, cathodoluminescence, and atomic force microscopy. We estimated the value of biaxial stress in pseudomorphic Al{sub x}Ga{sub 1−x}N layers grown on sapphire and silicon carbide substrates using HRXRD scans. The effect of biaxial stress on the room temperature band edge luminescence in pseudomorphic Al{sub x}Ga{sub 1−x}N/GaN layers for various aluminium compositions in the range of 0.2 < x < 0.3 was determined. The value of pressure coefficient of band gap was also estimated. The stress corrected bowing parameter in Al{sub x}Ga{sub 1−x}N was determined as 0.50 ± 0.06 eV. Our values match well with the theoretically obtained value of bowing parameter from the density functional theory.

• OSTI ID: 22412938
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 22 Vol. 117; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM COMPOUNDS
ATOMIC FORCE MICROSCOPY
CATHODOLUMINESCENCE
CHEMICAL VAPOR DEPOSITION
CONCENTRATION RATIO
DENSITY FUNCTIONAL METHOD
ELECTRON MOBILITY
ELECTRONIC STRUCTURE
ENERGY GAP
GALLIUM NITRIDES
LAYERS
PHOTOLUMINESCENCE
SAPPHIRE
SILICON CARBIDES
STRESSES
SUBSTRATES
TRANSISTORS
X-RAY DIFFRACTION