Enhancing concentrator monocrystalline Si solar cells by down conversion Ce3+-Yb3+ co-doped YAG phosphors

Abstract

Down conversion Ce3+-Yb3+ co-doped YAG phosphors are used to enhance concentrator monocrystalline silicon solar cells. The coating of polymethyl methacrylate (PMMA) mixed with the phosphors is deposited on the surface of the solar cells by spin-coating method. It is found that the solar cells with the phosphor coating always have higher conversion efficiency than the bare solar cells under different illumination intensities. This is attributed to the down conversion effect of the phosphors and the reduced reflection (especially in the wavelength range 350–550 nm). The reflection of the light emitted from the phosphor's particles at the air/PMMA interface also contributes to the improvement. The relative growth in the conversion efficiency of the solar cells with the phosphor coatings increases with the illumination intensity from 4.86% under 100 mW cm−2 to 6.04% under 400 mW cm−2 because the increase in the emission from the phosphors is faster than that of the illumination intensity when the illumination intensity increases.