Forward and reverse bias dependence of radiative recombination efficiency in green (In,Ga)N quantum well diodes
| Autor: | Kenzo Fujiwara, K. Ono, M. Horiguchi, K. Soejima, Akihiro Satake, H. Jimi |
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| Rok vydání: | 2012 |
| Předmět: |
Materials science
Photoluminescence business.industry Electroluminescence Condensed Matter Physics Molecular physics Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Photoexcitation Optoelectronics Quantum efficiency Spontaneous emission business Quantum tunnelling Quantum well Diode |
| Zdroj: | Physica E: Low-dimensional Systems and Nanostructures. 44:1278-1281 |
| ISSN: | 1386-9477 |
| DOI: | 10.1016/j.physe.2012.02.001 |
| Popis: | The relative internal quantum efficiency in green (In,Ga)N quantum well diodes is investigated by ac photoluminescence (PL) experiments using a lock-in technique under direct photoexcitation conditions where photoexcited carriers are generated only in the wells. The radiative recombination efficiency is found to be significantly varied as a function of both forward and reverse bias voltages. When the reverse bias is applied, the enhanced junction field causes a reduction of the PL intensity due to tunneling escape of carriers, although a blue-shift of PL emission energy is observed owing to the compensation of internal polarization field in the wells. A reduction of the PL intensity is also observed by increasing the forward bias, which we attribute to the reduced radiative recombination rate due to the decreased electron–hole wave function overlap in the wells. This finding suggests that the electroluminescence droop problem may also be caused as a result of reduced radiative efficiency under the high forward bias. |
| Databáze: | OpenAIRE |
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