Dependence of radiative and nonradiative recombination on carrier density and Al content in thick AlGaN epilayers
| Autor: | Arūnas Kadys, J. Jurkevičius, Maxim S. Shatalov, Ramūnas Aleksiejūnas, Gintautas Tamulaitis, R. Gaska, Michael Shur, J. Mickevičius, Žydrūnas Podlipskas, J. W. Yang |
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| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Acoustics and Ultrasonics Chemistry Al content Kinetics 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics Epitaxy 01 natural sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Abc model Charge-carrier density 0103 physical sciences Radiative transfer Quantum efficiency Atomic physics 0210 nano-technology Recombination |
| Zdroj: | Journal of Physics D: Applied Physics. 49:145110 |
| ISSN: | 1361-6463 0022-3727 |
| DOI: | 10.1088/0022-3727/49/14/145110 |
| Popis: | Dynamics of radiative and nonradiative recombination of non-equilibrium carriers is investigated in thick AlGaN epitaxial layers with Al content ranging from 0.11 to 0.71. The internal quantum efficiency (IQE) in the epilayers was obtained using two approaches: either estimated from PL measurements or calculated using the recombination coefficients of a simple ABC model, retrieved by fitting the kinetics of light induced transient gratings (LITG). At photoexcited carrier densities below ~1019 cm−3, both approaches provided similar IQE values indicating that the simple ABC model is applicable to analyze carrier recombination at such carrier densities. The increase in IQE at higher carrier densities slowed down for the values extracted from PL considerably faster than for those obtained from LITG transients. This discrepancy is explained in terms of the mixed nature of the rate coefficient B caused by the onset of the density-activated nonradiative recombination at high carrier densities. |
| Databáze: | OpenAIRE |
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