High-temperature light emission from InAs quantum dots

We study the photoluminescence (PL) properties of InAs/GaAs self-assembled quantum dots in a temperature range $\text{(T=300–500\hspace{0.05em}}\mathrm{K})$ above that reported to date. Various power excitation densities were used, allowing us to identify the important contribution of nonradiative channels in quenching the dot PL as the temperature is increased. The role played by the wetting layer on the dot PL intensity has been investigated in samples in which the separation of the dot and wetting layer levels is tuned by post-growth annealing. This experiment reveals that, at a high temperature (>300 K), the relative population of the dot and wetting layer levels is given by a Boltzmann distribution.