How much better are InGaN/GaN nanodisks than quantum wells—Oscillator strength enhancement and changes in optical properties

Journal Article · Mon Feb 03 00:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4864083· OSTI ID:22283253

Zhang, Lei; Hill, Tyler A.; Deng, Hui ^[1]; Lee, Leung-Kway; Teng, Chu-Hsiang; Ku, Pei-Cheng ^[2]

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1. Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109 (United States)
2. Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109 (United States)

We show over 100-fold enhancement of the exciton oscillator strength as the diameter of an InGaN nanodisk in a GaN nanopillar is reduced from a few micrometers to less than 40 nm, corresponding to the quantum dot limit. The enhancement results from significant strain relaxation in nanodisks less than 100 nm in diameter. Meanwhile, the radiative decay rate is only improved by 10 folds due to strong reduction of the local density of photon states in small nanodisks. Further increase in the radiative decay rate can be achieved by engineering the local density of photon states, such as adding a dielectric coating.

• OSTI ID: 22283253
• Journal Information: Applied Physics Letters, Vol. 104, Issue 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DIELECTRIC MATERIALS
ENERGY-LEVEL DENSITY
GALLIUM NITRIDES
INDIUM COMPOUNDS
OPTICAL PROPERTIES
OSCILLATOR STRENGTHS
PHOTONS
QUANTUM DOTS
RELAXATION
STRAINS