Fig. 3From: Enhanced Photovoltaic Performance of Dye-Sensitized Solar Cells by Efficient Near-Infrared Sunlight Harvesting using Upconverting Y2O3:Er3+/Yb3+ Phosphor Nanoparticles a Transmission spectra and b estimated absorption spectra of the dye-sensitized TiO2 (black solid line) and TiO2 + Y2O3:Er3+/Yb3+ (red solid line) photoelectrodes. The inset of a shows the reflectance spectra of the corresponding samplesBack to article page