Investigation of carrier relaxation dynamics in single CdSe/ZnSe self-organized quantum dot by time-resolved micro-photoluminescence

We have investigated carrier relaxation dynamics in single CdSe/ZnSe quantu m dot (QB) by time-resolved micro-photoluminescence (PL). The discrete shar p lines, originated from individual QD states, exhibit various rise and dec ay time constants. The decay times of the sharp lines from ground states an d excited states are estimated to be 700 similar to 800 psec and 400 simila r to 500 psec, respectively, and the rise times of the ground states become longer compared with those of the excited states. These results are in con trast to successive change of the rise and decay times observed in time-res olved macro-PL with varying the detection wavelength. The quasi-continuum h igher states with much shorter decay times are clearly observed over the di screte states of the QDs.