Tandem structured luminescent solar concentrator based on inorganic carbon quantum dots and organic dyes

Abstract

In this study, we demonstrate the simultaneous use of carbon quantum dots and organic dyes as highly emissive luminescent material in high performance tandem luminescent solar concentrator (LSC). The top LSC layer is based on carbon quantum dots (CQDs), while the bottom one is based on organic dye. The role of forster resonance energy transfer (FRET) is demonstrated in organic dyes in a bottom LSC. Moreover, the CQDs layer which has the capability to harvest ultraviolet (UV) and near-UV photons acts as a protective layer to improve the photo-stability of the organic dyes contained in bottom waveguide. The electrical measurements showed that the optical conversion efficiency (eta(opt)) and power conversion efficiency (eta(PCE)) of CQDs based single LSC are 5.62% and 1.03% respectively. While, eta(opt), and eta(PCE) the dye-LSC are 13.42% and 2.72% respectively. However, in the tandem LSC, overall eta(opt) and eta(PCE) are 16.32% and 3.2% respectively. Our results showed that tandem structured CQDs and dye based luminescent solar concentrators make the practical use of LSCs more feasible because of the unique properties such as good photostability and high efficiency.