Spatially Resolved Optical Efficiency Measurements of Luminescent Solar Concentrators

Luminescent solar concentrators (LSCs) are able to concentrateboth direct and diffuse solar radiation, and this ability has ledto great interest in using them to improve solar energy capture whencoupled to traditional photovoltaics (PV). In principle, a large-areaLSC could concentrate light onto a much smaller area of PV, thus reducingcosts or enabling new architectures. However, LSCs suffer from variousoptical losses which are hard to quantify using simple measurementsof power conversion efficiency. Here, we show that spatially resolvedphotoluminescence quantum efficiency measurements on large-area LSCscan be used to resolve various loss processes such as out-coupling,self-absorption via emitters, and self-absorption from the LSC matrix.Further, these measurements allow for the extrapolation of deviceperformance to arbitrarily large LSCs. Our results provide insightinto the optimization of optical properties and guide the design offuture LSCs for improved solar energy capture.