High internal quantum efficiency ultraviolet to green luminescence peaks from pseudomorphic m-plane Al{sub 1−x}In{sub x}N epilayers grown on a low defect density m-plane freestanding GaN substrate

Journal Article · Sun Dec 07 04:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4902315· OSTI ID:22402710

Hazu, K.; Furusawa, K.; Ishikawa, Y.; Onuma, T.; Ohtomo, T. ^[1]; Ikeda, H.; Fujito, K. ^[2]

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1. Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577 (Japan)
2. Gallium Nitride Department, Mitsubishi Chemical Corporation, 1000 Higashi-Mamiana, Ushiku, Ibaraki 300-1295 (Japan)

Structural and optical qualities of half-a-μm-thick m-plane Al{sub 1−x}In{sub x}N epilayers grown by metalorganic vapor phase epitaxy were remarkably improved via coherent growth on a low defect density m-plane freestanding GaN substrate prepared by hydride vapor phase epitaxy. All the epilayers unexceptionally suffer from uniaxial or biaxial anisotropic in-plane stress. However, full-width at half-maximum values of the x-ray ω-rocking curves were nearly unchanged as the underlayer values being 80 ∼ 150 arc sec for (101{sup ¯}0) and (101{sup ¯}2) diffractions with both 〈0001〉 and 〈112{sup ¯}0〉 azimuths, as long as pseudomorphic structure was maintained. Such Al{sub 1−x}In{sub x}N epilayers commonly exhibited a broad but predominant luminescence peak in ultraviolet (x ≤ 0.14) to green (x = 0.30) wavelengths. Its equivalent value of the internal quantum efficiency at room temperature was as high as 67% for x = 0.14 and 44% for x = 0.30. Because its high-energy cutoff commonly converged with the bandgap energy, the emission peak is assigned to originate from the extended near-band-edge states with strong carrier localization.

• OSTI ID: 22402710
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 21 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
GALLIUM NITRIDES
LUMINESCENCE
NEUTRON DIFFRACTION
PEAKS
QUANTUM EFFICIENCY
SUBSTRATES
ULTRAVIOLET RADIATION
VAPOR PHASE EPITAXY
X RADIATION