Author(s)

R. Naouari, W. Ouerghui, J. Martinez-Pastor, J. Gomis, M. A. Maaref, D. Granados, J. M. Garcia

Instituto de Ciencia de los Materials, Universidad de Valencia, Valencia, Spain.
Instituto de Microelectrónica de Madrid, Madrid, Spain.
Unité de Recherche des Physiques des Semiconducteurs et Capteurs, Institut Préparatoire aux Etudes Scientifiques et Techniques, Université Carthage, Tunis, Tunisia.

Carrier tunnelling through GaAs barriers of different thicknesses is investigated in vertically InGaAs/GaAs quantum rings (QR’s). Shorter PL decay time of the ground state emission of high-energy component in the sample with thicker spacer (1.5 nm) is ascribed to both tunnelling effect between the two QR families and vertical coupling between layers in the stacks. We found that tunnelling time between QR’s followed the Wentzel-Kramers-Brillouin (WKB) approximation. The non resonant tunnelling rate between QR’s is found to be different by one order of magnitude from the rate in quantum dots (QD’s).

Quantum Rings; Vertical Stack; Time Resolved Photoluminescence

R. Naouari, W. Ouerghui, J. Martinez-Pastor, J. Gomis, M. Maaref, D. Granados and J. Garcia, "Excitation Transfer in Vertically Stacked in (Ga)As/GaAs Quantum Rings," Journal of Modern Physics, Vol. 3 No. 6, 2012, pp. 471-475. doi: 10.4236/jmp.2012.36063.