Quantum size and shape effects on the excited states of ${\mathrm{In}}_x{\mathrm{Ga}}_{1-x}\mathrm{As}$ quantum dots

Resonant photoluminescence and excitation photoluminescence experiments have been carried out at low temperature in a number of (InGa)As/GaAs heterostructures. This has allowed us to investigate the dependence of the excited state energy of self-aggregated quantum dots (QD’s) on shape and size. Experimental results are compared with theoretical estimates of the QD density of states, and agreement and discrepancies with different theoretical approaches are highlighted. Finally, present results support recent reports of a strong In interdiffusion.