Dependence of the fundamental band gap of Al{sub x}Ga{sub 1{minus}x}N on alloy composition and pressure

Journal Article · Tue Jun 01 04:00:00 EDT 1999 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.370696· OSTI ID:341360

Shan, W; Ager, III, J W; Yu, K M; Walukiewicz, W ^[1]; Haller, E E ^[2]; Martin, M C; McKinney, W R ^[3]; Yang, W ^[4]

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1. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
2. Materials Sciences Division, Lawrence Berkeley National Laboratory
3. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
4. Honeywell Technology Center, Plymouth, Minnesota 55420 (United States)

Optical absorption studies were performed to investigate the dependence of the fundamental band gap of Al{sub x}Ga{sub 1{minus}x}N epitaxial films on Al content and applied hydrostatic pressure. The results of absorption measurements performed at atmospheric pressure yielded the variation of the band-gap energy E(x)=3.43+1.44x+1.33x{sup 2} eV for the Al{sub x}Ga{sub 1{minus}x}N system. Optical absorption edge associated with the direct {Gamma} band gap shifts linearly towards higher energy under applied pressure. By examining the pressure dependence of the absorption edge in samples with different AlN mole fractions and taking into account the difference of compressibility between the epitaxial films and sapphire substrate, the pressure coefficients for the direct {Gamma} band gaps of Al{sub x}Ga{sub 1{minus}x}N were determined. {copyright} {ital 1999 American Institute of Physics.}

• OSTI ID: 341360
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 12 Vol. 85; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTRA
ADVANCED LIGHT SOURCE
ALUMINIUM COMPOUNDS
ALUMINIUM NITRIDES
CHEMICAL VAPOR DEPOSITION
COMPRESSIBILITY
ENERGY GAP
GALLIUM COMPOUNDS
GALLIUM NITRIDES
OPTICAL PROPERTIES
PRESSURE DEPENDENCE
THIN FILMS