Numerical modeling of the size effect in CdSe/ZnS and InP/ZnSbased Intermediate Band Solar Cells

Abstract

New generation of solar cells based on the implementation of quantum dots in the intrinsic region has attracted much attention due to the fact to that it takes advantage of photons with energies lower than the band gap for achieving high solar conversion efficiency. However, there is still a need for optimizing many parameters related to the solar cells, such as the size of quantum dots and nature of semiconductor materials. The main objective of this study is to extend the current knowledge of the intermediate band solar cells. In particular, we analyze the effect of dot size on the photonic properties of CdSe/ZnS and InP/ZnS quantum dot solar cells by considering the Schrodinger equation within the effective mass approximation. It is demonstrated that quantum dot size is a critical parameter to be controlled for high efficiency CdSe/ZnS and InP/ZnS quantum dot solar cells. Our results show that open-circuit voltage weakly depends on dot size for both systems while short-circuit current density is increased with dot size increasing. As a result, maximum efficiency values of 31.73% and 32.90% are obtained for CdSe/ZnS and InP/ZnS, respectively under full concentrated light for a dot size of 2.3 nm, thereby demonstrating the potentiality of these proposed heterostructures.