Emission mechanisms in Al-rich AlGaN/AlN quantum wells assessed by excitation power dependent photoluminescence spectroscopy
- Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510 (Japan)
The optical properties of Al-rich AlGaN/AlN quantum wells are assessed by excitation-power-dependent time-integrated (TI) and time-resolved (TR) photoluminescence (PL) measurements. Two excitation sources, an optical parametric oscillator and the 4th harmonics of a Ti:sapphire laser, realize a wide range of excited carrier densities between 10{sup 12} and 10{sup 21 }cm{sup −3}. The emission mechanisms change from an exciton to an electron-hole plasma as the excitation power increases. Accordingly, the PL decay time is drastically reduced, and the integrated PL intensities increase in the following order: linearly, super-linearly, linearly again, and sub-linearly. The observed results are well accounted for by rate equations that consider the saturation effect of non-radiative recombination processes. Using both TIPL and TRPL measurements allows the density of non-radiative recombination centers, the internal quantum efficiency, and the radiative recombination coefficient to be reliably extracted.
- OSTI ID:
- 22413145
- Journal Information:
- Journal of Applied Physics, Vol. 117, Issue 7; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALUMINIUM NITRIDES
CARRIER DENSITY
ELECTRONS
EMISSION SPECTROSCOPY
EXCITATION
EXCITONS
GALLIUM NITRIDES
HOLES
OPTICAL PROPERTIES
PARAMETRIC OSCILLATORS
PHOTOLUMINESCENCE
QUANTUM EFFICIENCY
QUANTUM WELLS
REACTION KINETICS
RECOMBINATION
SAPPHIRE
SOLID-STATE PLASMA
TIME RESOLUTION