Experimental Results for Tailored Spectrum Splitting Metallic Nanofluids for c-Si, GaAs, and Ge Solar Cells

Spectrum splitting for hybrid photovoltaic/thermal (PV/T) collectors presents an opportunity to deliver higher combined efficiencies than either technology alone. Nanofluids offer an inexpensive alternative to spectrum splitting mirrors, and serve both as an optical filter and a heat transfer mechanism. This paper introduces experimental testing of spectrum splitting nanofluids for three cells: c-Si, GaAs, and Ge solar cells. The nanofluids were composed of combinations of core-shell silver-silica (Ag–SiO ₂ ) nanoplates as visible light absorbers and silica-coated gold and gold-copper nanorods as infrared absorbers. These nanoparticles were suspended in various concentrations in either a water or oil base fluid according to the spectral response of the solar cell. Indoor test results are presented for all three cell types. The Ag–SiO ₂ aqueous fluid, paired with a c-Si PV cell, delivered the highest combined efficiency, which indicates that this PV-nanofluid combination is a strong candidate for a low cost, high-efficiency spectrum splitting technology.