Radiative recombination of excitons in disk-shaped InAs/InP quantum dots

Recombination dynamics of excitons confined in disk-shaped $\mathrm{In}\mathrm{As}∕\mathrm{In}\mathrm{P}$ quantum dots is studied by time-resolved photoluminescence measurements. By comparing the result with that in a homologous ultrathin quantum well, it is revealed that the lateral confinement of excitons suppresses the thermal variation of the radiative recombination lifetime. The oscillator strength of the radiative transition is reduced with the decrease of the disk height, which is attributed to the increasing tunneling into the InP barrier of the exciton wave function.