Photoluminescence energy trend for ground and excited states in InAs quantum dots in InGaAs/GaAs QW structures

This paper presents the photoluminescence study at 80K and scanning photoluminescence spectroscopy investigation of the ground and multi excited states at 80 and 300K in InAs quantum dots (QDs) inserted in symmetric In0.15Ga0.85As/GaAs QW structures created at different QD growth temperatures. It is shown that some of the structures investigated exhibit a spatial long range variation of the average QD size in the QD ensemble across the sample. This long range QD size inhomogeneity was used for an investigation of the multi excited state energy trend versus ground state energy (or QD sizes). Experimental results were compared with the electron-hole level energy trend versus QD size predicted theoretically on the base of the 8-band k-p approach. Some anti correlation between experimental and theoretical results has been revealed and discussed. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.