Temperature Insensitivity of Optical Properties of InAs/GaAs Quantum Dots due to a Pregrown InGaAs Quantum Well

Both the peak position and linewidth in the photoluminescence spectrum of the InAs/GaAs quantum dots usually vary in an anomalous way with increasing temperature. Such anomalous optical behaviour is eliminated by inserting an In0.2Ga0.8As quantum well below the quantum dot layer in molecular beam epitaxy. The insensitivity of the photoluminescence spectra to temperature is explained in terms of the effective carrier redistribution between quantum dots through the In0.2Ga0.8As quantum well.

National Basic Research Programme of China 2006CB604904 National Natural Science Foundation of China 60776037 606760296030601060876086Supported by the National Basic Research Programme of China under Grant No 2006CB604904, and the National Natural Science Foundation of China under Grant Nos 60776037, 60676029, 60306010 and 60876086.