The integrated photoluminescence (PL) intensities of capped InP/GaInP quant
um dot structures have been measured as a function of temperature, The PL i
s 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 ind
icates that the major loss mechanism is thermal activation of excitons out
of the dots, followed by nonradiative recombination in the barriers. Identi
cal samples were grown without a capping layer in order to study the morpho
logy of the dots using an atomic force microscope (AFM). (C) 2000 Elsevier
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