Bilayer Luminescent Solar Concentrators with Enhanced Absorption and Efficiency for Agrivoltaic Applications
John Keil, Yaling Liu, Uwe Kortshagen, Vivian E. Ferry
Abstract
Luminescent solar concentrators are a promising route to environmentally integrated photovoltaics, acting as multifunctional systems that simultaneously generate electricity and transmit sunlight. For agrivoltaic applications, the ability to tune the transmission spectrum of the LSC to optimize crop growth while generating electricity is essential. Here we study a bilayer luminescent solar concentrator composed of a film of Si nanocrystals embedded in poly(methyl methacrylate) and a film of CdSe/CdS nanocrystals embedded in poly(cyclohexylethylene) for potential application in agrivoltaics. Position-dependent photoluminescence measurements demonstrate exceptionally high waveguide efficiency for the Si NC layer, and the films have relatively low diffuse transmission and reflection, indicating low levels of scattering. Using Monte Carlo ray-tracing simulations and experimental characterization, we show that the CdSe/CdS NC layer primarily increases the absorption efficiency of the Si NC-based LSC through a combination of direct absorption enhancement and sensitization. This bilayer system offers significant transmission spectrum tunability across the absorption bands of chlorophyll, which may be useful for agrivoltaic studies of different crop species.