Luminescent solar concentrator

Similarly, a graded refractive index optic fibre 1 square mm in cross section, and 1 metre long, with a luminescent coating might prove useful.

Suitable optical designs trap light emitted by the luminescent material in all directions, redirecting it so that little escapes the photovoltaic converters.

[4] Various articles have discussed the theory of internal reflection of fluorescent light so as to provide concentrated emission at the edges, both for doped glasses [2] and for organic dyes incorporated into bulk polymers.

Theoretically about 75-80 % of the luminescence could be trapped by total internal reflection in a plate with a refractive index roughly equal to that of typical window glass.

[6] Such an arrangement using a device with a high concentration factor should offer impressive economies in the investment in photovoltaic cells to produce a given amount of electricity.

[7] This takes into account: The relative merits of various functional components and configurations are major concerns, in particular: Luminescent solar concentrators could be used to integrate solar-harvesting devices into building façades in cities.

[13] These devices were composed of phosphorescent metal halide nanocluster (or Quantum dot) blends that exhibit massive Stokes shift (or downconversion) and which selectively absorb ultraviolet and emit near-infrared light, allowing for selective harvesting, improved reabsorption efficiency, and non-tinted transparency in the visible spectrum.

[14] LSCs based on cadmium selenide/zinc sulfide (CdSe/ZnS) and cadmium selenide/cadmium sulfide (CdSe/CdS) quantum dots (QD) with induced large separation between emission and absorption bands (called a large Stokes shift) were announced in 2007 and 2014 respectively[15][16][17] Light absorption is dominated by an ultra-thick outer shell of CdS, while emission occurs from the inner core of a narrower-gap CdSe.

The separation of light-absorption and light-emission functions between the two parts of the nanostructure results in a large spectral shift of emission with respect to absorption, which greatly reduces re-absorption losses.