Intrinsic luminescence-downshifting effects of Zn-based Mn-doped nanoparticle layers on Si solar cells

Abstract Luminescence downshifting (LDS) effects of Zn-based Mn-doped nanoparticles (NPs) on characteristics of Si solar cells are investigated. ZnSe:Mn/ZnS core-doped core/shell NPs and ZnSe/ZnS:Mn/ZnS shell-doped core/shell/shell NPs are deposited on glass plates using layer-by-layer method. It is found that shell-doped NPs are superior as LDS materials by measuring their optical properties. We deposit LDS layers made of shell-doped NPs on Si cells and measure their internal quantum efficiencies (IQEs) to examine LDS effects separately from the effects of reflection on LDS layers. We find that IQEs for 300–400 nm are more enhanced for cells with thicker LDS layers. IQE at 350 nm is calculated for Si cells with LDS layers coated using an analytical model for the transmittance of downshifted photons into Si cells. IQEs for the respective cells are in qualitative agreement with the measurements.