Simple and Robust Panchromatic Light Harvesting Antenna Composites via FRET Engineering in Solid State Host Matrices

The efficient harvesting of incident solar radiation is an important technical challenge for future world energy and chemical needs. Luminescent solar concentrators (LSCs) can efficiently harvest solar energy and concentrate it towards a useful output, such as photovoltaic cells or a photocatalytic reactor. LSCs are planar waveguides doped with luminescent materials that emit light into waveguide modes concentrating it towards the edges. However, large scale LSCs have been limited by the reabsorption of emitted photons. To overcome this, research has turned towards creating artificial light-harvesting systems that spatially and spectrally concentrate light through different donor and acceptor chromophores. Usually these chromophores are covalently linked and synthetically complex. We report a simple, versatile and highly efficient light-harvesting antenna system consisting of dyes suspended in a PMMA micro-powder. These composites absorb light throughout the visible region of the solar spectrum, efficiently funnel the energy via FRET and then re-emits it in the deep red with PLQY >95%. These composites are extremely robust and easy to process and can be incorporated into a variety of host matrices for applications. This system is characterised via continuous wave and transient spectroscopy. Proof-of-concept-devices and simulations show it to be well suited for use in LSCs.R.P. and A.R acknowledge funding from the EPSRC and the Winton Program for the Physics of sustainability. R.W.M. acknowledges funding from the Initiative and Networking Fund of the Helmholtz Association. N.J.L.K.D. thanks the Ernest Oppenhimer Trust for a research fellowship. We thank Mustafa Calgar for assistance with SEM measurements