Two-dimensional energy transfer between self-assembled quantum dots modulated by an external electric field

作者：Marques F A M^*; Monte A F G

来源：Journal of Applied Physics, 2013, 113(11): 113702.

DOI：10.1063/1.4795342

Energy transfer processes between InAs/GaAs self-assembled quantum dots within an intrinsic region of a p-i-n device have been studied. Three emission peaks associated with quantum dots (QDs) energy states could be identified in the photoluminescence (PL) spectrum in such a way that the energy transfer between lateral QDs could be individualized for each state. Using the spatially resolved micro-PL technique, several scans have been performed in the whole range of QDs emissions at different values of direct applied bias V-b. Curves were fitted according to the diffusion theory, and the parameters associated with the energy transfer (L) were plotted as a function of Vb and the QD recombination energy. We found that the energy transfer between QDs is faster for lower energy states and increases, with different rates, for each QD energy state by increasing the direct applied bias. The energy transfer process has been associated with the carrier diffusion within the barriers. We also found that the energy transfer between QDs decreases linearly with the electron-hole recombination energy. From this result, we conclude that the energy transfer phenomenon occurs following a Gaussian distribution of diffusing carriers, in which the concentrations of electron-hole pairs far away from the origin are just enough to fill the lower energy states of QDs.

• 出版日期2013-3-21