Microscopic mechanisms governing exciton-decay kinetics in type-II GaAs/AlAs superlattices

Journal Article · Sat Jul 15 04:00:00 EDT 1995 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.52.2682· OSTI ID:76473

Fu, L P; Bacalzo, F T; Gilliland, G D; Chen, R; Bajaj, K K ^[1]; Klem, J ^[2]; Wolford, D J ^[3]

---

1. Department of Physics, Emory University, Atlanta, Georgia 30322 (United States)
2. Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
3. Microelectronics Research Center and Department of Physics, Iowa State University, Ames, Iowa 50011 (United States)

We have measured the time- and space-resolved evolution of type-II excitons in GaAs/AlAs superlattices with various AlAs layer thicknesses, at temperatures ranging from 1.8 to 30 K. Our photoluminescence (PL) time decay and transport results demonstrate that the exciton-decay kinetics at low temperatures are entirely determined by intrinsic radiative recombination, whereas at higher temperatures, the PL time decays are dominated by nonradiative defect trapping processes. We show that these nonradiative decays do not occur within the layers but are instead localized at the heterointerfaces. The measured lifetimes at 30 K are consistent with our model calculations based on this interpretation. Furthermore, the superlattice and interface-disorder-induced {Gamma}-{ital X} mixing potentials are determined from our low-temperature exciton lifetimes to be 1.3 and 0.2 meV, respectively.

• Research Organization: Sandia National Laboratory
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 76473
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 4 Vol. 52; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ARSENIDES
DECAY
EXCITONS
GALLIUM ARSENIDES
LIFETIME
PHOTOLUMINESCENCE
SUPERLATTICES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0013-0065 K
TIME RESOLUTION