Long lived photoexcited electron-hole pairs in modulation doped GaAs/AlGaAs quantum wells studied by intersubband spectroscopy
| Autor: | Yuval Garini, Arthur C. Gossard, Eitan Ehrenfreund, James L. Merz, Arza Ron, K.-K. Law, E. Cohen |
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| Rok vydání: | 1994 |
| Předmět: |
Free electron model
Chemistry business.industry Carrier generation and recombination Doping Electron Condensed Matter Physics Electronic Optical and Magnetic Materials Materials Chemistry Optoelectronics Spontaneous emission Electrical and Electronic Engineering Atomic physics Spectroscopy Absorption (electromagnetic radiation) business Quantum well |
| Zdroj: | Solid-State Electronics. 37:1199-1202 |
| ISSN: | 0038-1101 |
| DOI: | 10.1016/0038-1101(94)90388-3 |
| Popis: | We present a study of the e 1- e 2 intersubband absorption in modulation doped GaAs/Al 0.3 Ga 0.7 As MQW's that are photoexcited by interband radiation. A comprehensive study of the photoinduced absorption (PIA) strength as a function of exciting (laser) intensity and modulation frequency indicates that only a subgroup of the photoexcited electrons contribute to the PIA. These electrons are long lived in MQW's with a 2DEG density in the range of 1–×10 10 cm −2 . The existence of long lived electrons is explained by a model based on localized, photoexcited holes, that have a reduced radiative recombination rate with the 2DEG. We calculate this recombination rate and show that it is much longer than that of free electrons and holes. |
| Databáze: | OpenAIRE |
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