Fig. 1. (Color online) Schematic for the heteroepitaxy structure of InAs/GaAs QDs.

Fig. 2. (Color online) (a) The PL spectrum of the as-grown QDs sample under 14 mW of excitation power at 16 and 300 K respectively. (b) The Gaussian fitting diagram of the PL spectrum of the as-grown QDs sample at 16 K, with the dash-dot lines showing the Gaussian fitting of different emission peaks.

Fig. 3. (Color online) The normalized PL spectra of as-grown QDs and QDs annealed at various temperatures obtained at (a) 16 K and (b) 300 K under an excitation power of 14 mW. Inset: The PL peak energy of QDs at (a) T = 16 K and (b) T = 300 K with the change of annealing temperature, with the red curve representing small QDs and the black curve representing large QDs.

Fig. 4. (Color online) (a) The PL spectral width of QDs at T = 16 K (denoted by red curve) and T = 300 K (denoted by blue curve) with the change of annealing temperature. (b) The integrated PL intensity at T = 16 K (denoted by red curve) and T = 300 K (denoted by blue curve) with the change of annealing temperature.

Fig. 5. (Color online) The top half of the figure shows the power-dependent PL spectrum of samples annealed at (a) 750, (b) 800, (c) 850, and (d) 900 °C recorded at 300 K. The PL spectrum of the annealed sample under an excitation power of 40 mW was extracted and Gaussian fitting was performed, as shown in the lower part of the figure.