Structural and Optical Properties of Self-assembled InAs Quantum Dots as a Function of Rapid Thermal Annealing Temperature

We present the effects of rapid thermal annealing (RTA) temperature on the structural and optical properties of self-assembled InAs quantum dot (QD) structures grown on GaAs substrates by molecular beam epitaxy (MBE). The photoluminescence (FL) measurements are performed in a dosed-cyde refrigerator as a function of temperature for the unannealed and annealed sainples. RTA at higher temperature results in the increase in island size, the corresponding decrease in the density of islands, and the redshift in the PL emission from the islands. The temperature dependence of the PL peak energy for the InAs QDs is well expressed by the Varshni equation. The thermal quenching activation energies for the samples unannealed and annealed at 600 degrees C are found to be 2515 meV and 171 5 meV, respectively.