Luminescence blinking in Eu3+ doped yttrium oxysulfide (Y2O2S:Eu3+) quantum-dot ensembles: Photo-assisted relaxation of surface state(s)

Ensembles of Y2O2S:Eu3+ widegap semiconductor nano-crystals exhibit ON–OFF fluorescence blinking phenomenon, which mimic II–VI semiconductor quantum-structures. Attempt has been made to explain this phenomenon under the ambit of diffusion controlled electron transfer (DCET) model. Insights derived using opto-impedance technique in conjunction with the DCET model clearly establish the relaxation of surface state(s) through a diffusion process. Ensembles of Y2O3:Eu3+ nano-crystals, the insulating counterpart investigated for comparison does not show such fluorescence blinking.