J. Phys. Colloques
Volume 48, Numéro C5, Novembre 19873rd International Conference on Modulated Semiconductor Structures
|Page(s)||C5-525 - C5-528|
J. Phys. Colloques 48 (1987) C5-525-C5-528
OPTICAL STUDIES OF TYPE I AND TYPE II RECOMBINATION IN GaAs-AlAs QUANTUM WELLSK.J. MOORE, P. DAWSON et C.T. FOXON
Philips Research Laboratories, GB-Redhill, RH1 5HA, Surrey, Great-Britain
In this paper we report the results of a systematic investigation on the effects of electronic coupling on a series of GaAs-AlAs multiple quantum well samples in which the thickness of the GaAs layers was fixed at ~ 25Å and the AlAs thickness varied between samples from 39Å to 6Å. Using the techniques of photoluminescence and photoluminescence excitation spectroscopy we have followed the positions of both the Ɖ-related direct gap and the Ɖ-X pseudo-indirect gap as a function of AlAs thickness. As the AlAs thickness is reduced we observe the system change from a type II to a type I band alignment and measure this crossover at ~ 13Å of AlAs in these samples.