Experimental determination of Auger capture coefficients in self-assembledquantum dots

Time-resolved studies of the wetting layer photoluminescence are combined w ith state-filling spectroscopy of the quantum dot and wetting layer emissio n to obtain carrier transfer rates from the wetting layer to the quantum do t states. With this method, capture rates can be measured for constant carr ier concentrations in the wetting layer. The results show that the capture efficiency increases with the carrier concentration in the wetting layer, i ndicating the important role of Auger processes in the capture dynamics. In the analysis, the concept of capture cross section per unit time is introd uced, and this is used to determine the single dot Auger capture coefficien t in self-assembled dots. The value obtained can in principle be used as an input to model carrier capture in all self-assembled dot devices with simi lar dot layers.