cw photoluminescence determination of thermally activated fast {ital X}{r_arrow}{Gamma} interlayer electron scattering in type-II GaAs/AlAs superlattices
- Department of Physics, Emory University, Atlanta, Georgia 30322 (United States)
- Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
We have observed dominant type-I photoluminescence from type-II GaAs/AlAs superlattices at temperatures higher than 150 K. The measured type-I to type-II photoluminescence intensity ratio at various temperatures is quantitatively described by a three-level rate-equation model. Our results demonstrate the importance of the {ital X}{r_arrow}{Gamma} real-space charge-transfer (RSCT) process, i.e., the interlayer electron scattering from the AlAs {ital X} valleys back to the GaAs {Gamma} minimum, which leads to the thermally activated type-I emission in type-II structures. Furthermore, we have determined the temperature dependence of this {ital X}{r_arrow}{Gamma} interlayer electron scattering from 2 to 300 K. The {ital X}{r_arrow}{Gamma} RSCT time is determined to be about 20 ps at {ital T}=300 K. Finally, our results demonstrate that cw PL measurements are useful in determining ultrafast (fs) scattering times.
- Research Organization:
- Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 74046
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 51, Issue 24; Other Information: PBD: 15 Jun 1995
- Country of Publication:
- United States
- Language:
- English
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