We have investigated the recombination dynamics in self-assembled InP/GaP quantum dots by means of time-resolved photoluminescence measured at low temperatures between 2 and 100 K and high hydrostatic pressure up to 2 GPa. Due to the high-power levels for pulsed excitation, the quantum dot emission exhibits two components with typical decay times of 5 and 30 ns, corresponding to direct Γ -Γ and X -Γ interband recombination processes, respectively. These decay times appear to be independent of pressure. At a very low pressure of about 0.1 GPa the intensity of the dot emission drops abruptly relative to that of the wetting layer indicating a switching off of a carrier relaxation channel.

We carried out micro-photoluminescence studies of doped multiple quantum wire structures grown by the cleaved-edge overgrowth technique in the GaAs/AlGaAs material system. The wires are defined in a quantum well whose potential is modulated by adjacent alternating negatively and positively charged layers. We observed strong band gap renormalization effects in the quantum wires indicating that they are densely populated. The measured recombination energies are in good agreement with a simple quantum mechanical calculation. Nevertheless, the design of the sample appears to be not suitable for light scattering studies of the one dimensional (1D) electron gas, for the 1D confinement strongly depends on photoexcitation.