Confined multiexciton states of GaAs/AlGaAs quantum dots grown on a (411)AGaAs surface

We have investigated the micro photoluminescence (micro-PL) spectra of a si ngle GaAs/AlGaAs quantum dot (QD) grown on a (411)A GaAs substrate, and obs erved sharp luminescence lines. These luminescence lines are classified int o three types in terms of their excitation-power dependence. For one of the m the intensity increases linearly with excitation power density, and the o thers that appear at the lower and higher energy sides of the linear one ex hibit superlinear dependence. The difference in the excitation-power depend ence reflects the number of excitons created in a QD, namely, the linear de pendence originates from the lowest state of a confined exciton, and the ot hers from biexcitonic and multiple exciton states.