Time-resolved detection of many-particle hole states in InAs/GaAs quantum dots using a two-dimensional hole gas up to 77 K

We demonstrate the detection of many-particle hole states in self-organized InAs/GaAs quantum dots (QDs) using an adjacent two-dimensional hole gas (2DHG) as detector for temperatures up to 77 K. capacitance-voltage (C-V) measurements as well as time-resolved current measurements in the 2DHG resolve a structure of six distinct peaks which are related to the many-particle hole states in the QD ensemble. The time constants of the capture and emission processes for each individual many-particle hole state are extracted and the underlying emission processes are identified. An equivalent circuit model yields the gate voltage dependent lever-arm and the level-splittings of the many-particle hole states. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)