Carrier Relaxation and Recombination in (GAAS) (ALAS) Short Period Superlattices
We report on investigations of carrier relaxation and recombination in (GaAs)m (AlAs)n short period supperlattices applying luminescence excitation spectroscopy and picosecond photoluminescence. A transition from a type 1 to type 2 superlattice is observed in symmetric structures (m = n) around m ≃ 8 − 10. The recombination times in the type 1 superlattices decrease continuously with decreasing GaAs and AlAs layer thickness down to 250 ps for a (GaAs)3(AlAs)1 superlattice structure. The luminescence decay in the type 2 samples is slower by orders of magnitude at low temperatures. A very fast high energy luminescence transition is additionally observed in type 2 structures due to recombination of nonthermalized electrons in the GaAs layers. The rapid disappearance of the luminescence reveals the fast scattering from г-ike conduction band states of the GaAs into X-like states of the AlAs with a characteristic time constant appreciably smaller than 20 ps.
KeywordsLuminescence Decay Nonthermalized Electron Superlattice Structure Carrier Relaxation Conduction Band State
Unable to display preview. Download preview PDF.
- P. Dawson, K.J. Moore, and C.T. Foxon, Proc. SPIE Symp. on Quantum Well and Superlattice Physics, vol. 792, 207 (1987)Google Scholar
- B.A. Wilson, C.E. Bonner, R.C. Spitzer, P. Dawson, K.J. Moore, and C.T. Foxon, J. Vac. Sci. Technol. B 6, 1156 (1988)Google Scholar
- J. Nagle, M. Garriga, W. Stolz, T. Isu, and K. Ploog, J. de Physique 48, C5–495 (1987)Google Scholar
- P.P. Ruden, D.C. Engelhardt, and J.K. Abrokwah, J. Appl. Phys. 61, 2294 (1986)Google Scholar
- B. Deveaud, B. Lambert, A. Chomette, F. Clerot, A. Regreny, J. Shah, T. Damen, and B. Sermage, see article in this book.Google Scholar