ZnSe/ZnS core-shell quantum dots incorporated with Ag nanoparticles as luminescent down-shifting layers to enhance the efficiency of Si solar cells

Abstract

Luminescent down-shifting (LDS) is a spectral conversion method for improving the short-wavelength response of Si-based solar cell by transforming shorter wavelength (200 nm-400 nm) into longer wavelength (>400 nm). In this paper, LDS efficiency was enhanced through incorporating Ag nanoparticles into ZnSe/ZnS quantum dots (QDs), as demonstrated by photoluminescence (PL) spectra and finite-difference time-domain (FDTD) simulation results. The mixed Ag/ZnSe/ZnS QDs were spin-coated on the surface of manufactured Si-solar cell so as to efficiently utilize LDS properties. The external quantum efficiency (EQE) and short-circuit current density (Jsc) of Ag/ZnSe/ZnS QDs–Si hybrid solar cell were respectively increased by 30% and 7.5% compared to those of ZnSe/ZnS–Si hybrid solar cell. These improvements were mainly ascribed to localized surface plasmonic (LSP) enhancement effect of Ag nanoparticles. Such small but distinct improvements are expected to provide the theoretical basis and technical support for the development of photovoltaic devices in the future.