Nonradiative energy transfer between vertically coupled indirect and direct bandgap InAs quantum dots

Nonradiative energy transfer from indirect bandgap InAs/AlAs quantum dots (QDs) to direct bandgap InAs/AlGaAs QDs was studied by steady-state and transient photoluminescence. We demonstrate that long excitonic lifetime in donor InAs/AlAs QDs allows one to extend the efficient exciton energy transfer between coupled QDs to distances up to 9 nm. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3532102]