Research on the luminescent solar concentrator (LSC) over the past thirty‐odd years is reviewed. The LSC is a simple device at its heart, employing a polymeric or glass waveguide and luminescent molecules to generate electricity from sunlight when attached to a photovoltaic cell. The LSC has the potential to find extended use in an area traditionally difficult for effective use of regular photovoltaic panels: the built environment. The LSC is a device very flexible in its design, with a variety of possible shapes and colors. The primary challenge faced by the devices is increasing their photon‐to‐electron conversion efficiencies. A number of laboratories are working to improve the efficiency and lifetime of the LSC device, with the ultimate goal of commercializing the devices within a few years. The topics covered here relate to the efforts for reducing losses in these devices. These include studies of novel luminophores, including organic fluorescent dyes, inorganic phosphors, and quantum dots. Ways to limit the surface and internal losses are also discussed, including using organic and inorganic‐based selective mirrors which allow sunlight in but reflect luminophore‐emitted light, plasmonic structures to enhance emissions, novel photovoltaics, alignment of the luminophores to manipulate the path of the emitted light, and patterning of the dye layer to improve emission efficiency. Finally, some possible ‘glimpses of the future’ are offered, with additional research paths that could result in a device that makes solar energy a ubiquitous part of the urban setting, finding use as sound barriers, bus‐stop roofs, awnings, windows, paving, or siding tiles.

Luminescent solar concentrators (LSCs) are versatile devices that complement standard photovoltaic cells. , M. G. Debije and P. P. C. Verbunt discuss how the LSC absorbs incoming sunlight with luminescent materials embedded in a polymer host, and re‐emits this light at longer wavelengths, the trapped light traveling down the polymer sheet to concentrate at the edges where it is converted into electricity via a small attached photovoltaic cell. The LSC's coloration, adaptability of shape and size, and performance in varied light conditions could make it perfectly suited for use in the urban setting. The authors would like to extend their thanks to Q. D. Nguyen and S. Tsoi for assistance in preparing the cover image.

A luminescent solar concentrator (LSC) is a potential low‐cost enhancement of the standard large‐area silicon photovoltaic panels for the generation of electricity from sunlight. In this work, guest–host systems are investigated using anisotropic fluorescent dyes and liquid crystal mesogens to control the direction of emitted light in the LSC. It is determined that up to 30% more light is emitted from the edge of an LSC waveguide with planar dye alignment parallel to the alignment direction than from any edge of an LSC with no alignment (isotropic). The aligned samples continue to show dichroic performance after additions of both edge mirrors and rear scattering layer.

The surface and edge emissions from dye-filled and dye-topped polycarbonate and polymethyl methacrylate luminescent solar concentrators were measured. We demonstrate that about 40-50% of the absorbed light energy (and 50-70% of the photons) is lost through the top and bottom surfaces of the filled waveguide. In most cases the escape cone losses are greater at the top than the bottom surface.

Luminescent solar concentrators would allow for high concentration if losses by reabsorption and escape could be minimized. We introduce a phosphor with close-to-optimal luminescent properties and hardly any reabsorption. A problem for use in a luminescent concentrator is the large scattering of this material; we discuss possible solutions for this. Furthermore, the use of broad-band cholesteric filters to prevent escape of luminescent radiation from this phosphor is investigated both experimentally and using simulations. Simulations are also used to predict the ultimate performance of luminescent concentrators. ©2012 Optical Society of America