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The luminescent solar concentrator (LSC) was first proposed in the 1970s as a means to reduce the high cost of generating solar energy. The basic design was simple: a large transparent plate doped with an appropriate luminescent material which is able to absorb both direct and diffuse sunlight, and then guide photons produced by photoluminescence to its narrow edges where they are converted by photovoltaic cells. Unfortunately, the LSC has suffered from numerous efficiency losses and short lifetimes. Therefore, new luminescent species and novel approaches are needed for its practical application. Novel luminescent species studied in this thesis include arrays of vertical, self-aligned CdSe/CdS nanorods. The nanorods emit preferentially in the waveguiding plane and were characterised to ascertain the extent of self-alignment, and to determine their viability and this alignment technique for LSCs. Furthermore, a number of generations of bio-derived Phycobillisomes, a light absorbing pigment found in species of red algae, have been also been investigated and are a possible source of cheap and abundant luminescent material. Lastly, several luminescent species consisting of metal complexes and oligomers with high Stokes-shift were investigated. High Stokes-shift materials are essential if LSC efficiencies are to be increased as they mitigate the re-absorption that generally constitutes the dominant loss mechanism. This thesis features two novel LSC applications. The first is a large area, flexible LSC system for portable power generation. Computational raytrace simulations reveal the device is feasible but will require high Stokes-shift materials. The second novel approach utilises a tandem LSC system in conjunction with a photoelectrochemical cell (PEC). In the tandem design the upper concentrator provides blue light to excite a Fe2O3 photoanode for water oxidation while the lower concentrator provides red light that is converted by Si cells producing sufficient voltage to enable hydrogen production at a Pt electrode contained within the PEC. |
