Recombination Enhancement due to Carrier Localization in Quantum Well Structures

Abstract

Picosecond luminescence experiments on $\mathrm{GaAs}/{\mathrm{Al}}_{x}{\mathrm{Ga}}_{1\ensuremath{-}x}\mathrm{As}$ quantum well structures reveal a significant influence of localization on the transition probabilities of photoexcited carriers. The spontaneous lifetime of electrons and holes within the quantum well decreases with well thickness ${L}_{z}$ from 1 ns for ${L}_{z}=14$ nm to 350 ps for ${L}_{z}=5$ nm because of the enhanced recombination due to localization of the carriers.