Low Density Self-Assembled InAs/GaAs Quantum Dots Grown by Metal Organic Chemical Vapour Deposition

The self-assembled InAs quantum dots (QDs) on GaAs substrates with low density (5×10⁸cm^-2) are achieved using relatively higher growth temperature and low InAs coverage by low-pressure metal-organic chemical vapour deposition. The macro-PL spectra exhibit three emission peaks at 1361, 1280 and 1204nm, corresponding to the ground level (GS), the first excited state (ES1) and the second excited state (ES2) of the QDs, respectively, which are obtained when the GaAs capping layer is grown using triethylgallium and tertiallybutylarsine. As a result of micro-PL, only a few peaks from individual dots have been observed. The exciton--biexciton behaviour was clearly observed at low temperature.