Concentrating aggregation-induced fluorescence in planar waveguides: a proof-of-principle

The photophysical properties of fluorescent dyes are key determinants in the performance of luminescent solar concentrators (LSCs). First-generation dyes--coumarin, perylenes, and rhodamines--used in LSCs suffer from both concentration quenching in the solid-state and small Stokes shifts which limit the current LSC efficiencies to below theoretical limits. Here we show that fluorophores that exhibit aggregation-induced emission (AIE) are promising materials for LSC applications. Experiments and Monte Carlo simulations show that the optical quantum efficiencies of LSCs with AIE fluorophores are at least comparable to those of LSCs with first-generation dyes as the active materials even without the use of any optical accessories to enhance the trapping efficiency of the LSCs. Our results demonstrate that AIE fluorophores can potentially solve some key limiting properties of first-generation LSC dyes.