Temperature influence on optical charging of self-assembled InAs/GaAs semiconductor quantum dots

It is demonstrated that the photoluminescence spectra of single self-assemb led InAs/GaAs quantum dots are very sensitive to excitation energy and crys tal temperature. This is qualitatively explained in terms of the effective diffusivity of photogenerated particles, which affects the capture probabil ity of the quantum dot. As a consequence, this opens the possibility of con trolling the average number of excess electrons in the quantum dot by optic al means. This technique may be used as a simple tool to create and study c harged exciton complexes without any specially fabricated samples. (C) 2001 American Institute of Physics.