Increased short-circuit current density and external quantum efficiency of silicon and dye sensitised solar cells through plasmonic luminescent down-shifting layers

•We fabricated luminescent down-shifting layers (LDS) of CdSe/ZnS QDs.•We synthesised Ag NPs and fabricated plasmonic-LDS of QDs/Ag NPs composites layers.•We compared performance of c-Si and DSSC devices with and without pLDS layers.•Plasmonic interaction has significantly improved absorption and emission of QDs.•pLDS layer significantly increased the Jsc and EQE of solar cells between 300 and 500 nm.

Luminescent down-shifting (LDS) is a purely optical method to improve the short-wavelength response of photovoltaics by red-shifting the incident solar spectrum. This work is the first to investigate plasmonic LDS (pLDS) layers applied to c-Si and DSSC solar cells. The addition of pLDS composite layers containing core–shell quantum dots CdSe/ZnS was demonstrated to increase the short circuit current density (Jsc) of c-Si and DSSC devices between 300 and 500 nm, where the QDs is most absorbing. Up to ∼22% (relative) increase has been achieved for both cells when compared with cells with no pLDS layers. External quantum efficiency measurements have shown significant enhancement where the solar cells have poor optical response, below 500 nm, while increased efficiency was confirmed with current–voltage (I–V) measurements.