Widely tunable intersubband energy spacing of self-assembled InAs/GaAs quantum dots due to interface intermixing

Abstract

The effect of rapid thermal annealing (RTA) on the optical properties of the self-assembled InAs/GaAs quantum dots (QD) by using photoluminescence techniques is studied experimentally. Significant reduction of the energy spacing between ground state and excited state emissions was observed. The high resolution X-ray diffraction (HRXRD) experiments show strong evidence of the interface atoms interdiffusion. Results show that postgrowth RTA can be used to widely tune the intersubband energy spacing between the ground state and the excited state of the InAs/GaAs QD. This gives a range in wavelength tunability for applications like infrared detectors and lasers based on intersubband transitions.