  The dynamic properties of light-emitting single-electron transistors (LESETs)
made from quantum dots are theoretically studied by using nonequilibrium
Green's function method. Holes residing at QD created by small ac signals added
in the base electrode of valence band lead to the exciton assisted tunnelling
level for the electron tunnelling from emitter to collector, it is therefore
such small signals can be amplified. LESETs can be employed as efficient
single-photon detectors.
