title: Optimization of carrier multiplication for more effcient solar cells: the case of Sn quantum dots.
abstract: We present calculations of impact ionization rates, carrier multiplication yields, and solar-power conversion efficiencies in solar cells based on quantum dots (QDs) of a semimetal, α-Sn. Using these results and previous ones on PbSe and PbS QDs, we discuss a strategy to select QDs with the highest carrier multiplication rate for more efficient solar cells. We suggest using QDs of materials with a close to zero band gap and a high multiplicity of the bands in order to favor the relaxation of photoexcited carriers by impact ionization. Even in that case, the improvement of the maximum solar-power conversion efficiency appears to be a challenging task.
authors.affiliation: IEMN, Department ISEN, 41 boulevard Vauban, 59046 Lille Cedex, France.
authors.forename: Guy
authors.initials: G
authors.lastname: Allan
authors.forename: Christophe
authors.initials: C
authors.lastname: Delerue