Efficiency droop in GaN LEDs at high current densities: Tunneling leakage currents and incomplete lateral carrier localization in InGaN/GaN quantum wells
| Autor: | N. I. Bochkareva, Yury Georgievich Shreter, Y. T. Rebane |
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| Rok vydání: | 2014 |
| Předmět: |
Physics
Condensed matter physics business.industry Condensed Matter Physics Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials law.invention law Optoelectronics Voltage droop Tunnel injection business Quantum well Quantum tunnelling Quasi Fermi level Leakage (electronics) Diode Light-emitting diode |
| Zdroj: | Semiconductors. 48:1079-1087 |
| ISSN: | 1090-6479 1063-7826 |
| DOI: | 10.1134/s1063782614080065 |
| Popis: | The phenomenon of the emission efficiency droop of InGaN/GaN quantum wells (QWs) in light-emitting diode p-n structures is studied. The influence exerted by two basic processes on the emission efficiency is considered: tunnel injection into a QW and incomplete lateral carrier localization in compositional fluctuations of the band-gap width in InGaN. The sharp efficiency peak at low currents and the rapid efficiency droop with increasing current are due to tunneling leakage currents along extended defects, which appear as a result of a local increase in the electron hopping conductivity via the depletion n region and a corresponding local decrease in the height of the injection p barrier. A less sharp efficiency peak and a weak, nearly linear, decrease in efficiency with increasing current are caused by incomplete lateral carrier localization in the QW due to slowing-down of the carrier energy-relaxation rate and to the nonradiative recombination of mobile carriers. |
| Databáze: | OpenAIRE |
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