Temperature dependence of InP/GaInP quantum dot photoluminescence

The integrated photoluminescence (PL) intensities of capped InP/GaInP quantum dot structures have been measured as a function of temperature. The PL is found to decrease by up to four orders of magnitude as the temperature is raised from 18 to 300 K. The temperature data show an Arrhenius behaviour characterised by three activation energies. Analysis of this dependence indicates that the major loss mechanism is thermal activation of excitons out of the dots, followed by nonradiative recombination in the barriers. Identical samples were grown without a capping layer in order to study the morphology of the dots using an atomic force microscope (AFM).