Influence of the energy transfer in a single donor-acceptor pair on the photon distribution functions in its fluorescence

► Single donor molecule with a 'dark' state exhibits blinking fluorescence. ► Single acceptor molecule without 'dark' state exhibits CW-fluorescence. ► Acceptor fluorescence acquires blinking character at strong DA energy transfer. ► Photon distribution functions for donor/acceptor fluorescence have been derived. ► Shape of these functions expresses character of donor and acceptor fluorescence.