Exciton Dissociation in CdSe/CdTe Heterostructure Nanorods.

Type-II heterostructure nanorods hold good prospects for efficient charge separation in nano solar cells. Here we employed local density approximation (LDA) quality plane wave pseudopotential methods to study exciton dissociation in CdSe/CdTe collinear nanorods. We corrected the LDA band gap by approximating GW equations, and studied the correlation effect with configuration interaction methods. The calculated binding energy and radiative decay time of the charge transfer excitons agree well with experiments. The thermally activated escaping time is estimated to be shorter than the radiative recombination time, indicating the possibility of exciton dissociation if the nonradiative channel is ignored.