Spectral Selectivity of CdTe Cells with Substrate Configuration for Photovoltaic/Thermal Applications

Existing photovoltaic cells with high infrared emissivity generate huge radiative heat loss in photovoltaic/thermal applications and degrade the photothermal performance. The purpose of this work is to evaluate the full spectral absorptivity of CdTe cells to find a spectrally selective photovoltaic cell for photovoltaic/thermal applications. To this end, the solar absorptivity and mid-infrared thermal emissivity of CdTe cells were tested by ellipsometry, UV-Vis-NIR spectrophotometer, and Fourier transform infrared spectrometer. The experimental results show that the AM 1.5 solar spectrum weighted absorptivity of the substrate configuration CdTe cell reaches 0.91, and the mid-infrared emissivity is only 0.29, while the superstrate configuration cell emissivity is as high as 0.9. Further research shows that substrate configuration with a transparent conductive layer on top can be flexibly grown on metal foils and has spectral selectivity with high solar absorptivity and low mid-infrared emissivity should be considered in the future for photovoltaic/thermal applications.