In this paper, both the performance and stability of luminescent flat plate concentrator (LFPC) plates in combination with mc-Si photovoltaic cells are studied. It is shown that the electrical current of a silicon solar cell attached to the luminescent plate is improved by a factor 1.5 using a LFPC containing a single dye. It is also shown that most of the dyes are not stable in the polymer plates that are currently used. Screening of the stability of several other dyes indicates that the stability is strongly dependent on the type of dye and the polymer matrix, e.g., additives or the monomer residues.

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One of the major loss mechanisms in state of the art photovoltaic cells is spectral loss resulting from inefficient use of ultraviolet photons and the lack of absorption of infrared photons by the solar cell. For a Si solar cell, e.g., spectral losses alone result in over 55% loss of the energy of the solar spectrum. Converting the spectrum of the incoming light such that it has a better match with the absorption spectrum of the solar cell can reduce spectral losses, especially in the case of a small absorption band, such as for dye sensitized solar cells and polymer solar cells. In this paper it is shown that the ultraviolet response of a multicrystalline silicon solar cell and polymer solar cell can be enhanced by application of a polymer coating doped with a luminescent dye. An increase in the power conversion efficiency is obtained for coatings with luminescent dyes with an absorption onset <450 nm. Coatings with luminescent dyes that absorb at higher wavelengths give rise to lower power conversion efficiencies. When applied to a dye sensitized solar cell, a decrease in the cell performance is observed.

Luminescent concentrator (LC) plates with different dyes were combined with standard multicrystalline silicon solar cells. External quantum efficiency measurements were performed, showing an increase in electrical current of the silicon cell (under AM1.5, 1 sun conditions, at normal incidence) compared to a bare cell. The influence of dye concentration and plate dimensions are addressed. The best results show a 1.7 times increase in the current from the LC/silicon cell compared to the silicon cell alone. To broaden the absorption spectrum of the LC, a second dye was incorporated in the LC plates. This results in a relative increase in current of 5-8% with respect to the one dye LC, giving. Using a ray-tracing model, transmission, reflection and external quantum efficiency spectra were simulated and compared with the measured spectra. The simulations deliver the luminescent quantum efficiencies of the two dyes as well as the background absorption by the polymer host. It is found that the luminescent quantum efficiency of the red emitting dye is 87%, which is one of the major loss factors in the measured LC. Using ray-tracing simulations it is predicted that increasing the luminescent quantum efficiency to 98% would substantially reduce this loss, resulting in an increase in overall power conversion efficiency of the LC from 1.8 to 2.6%

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