Enhanced Photovoltaic Performance of Dye-Sensitized Solar Cells by Efficient Near-Infrared Sunlight Harvesting using Upconverting Y2O3:Er3+/Yb3+ Phosphor Nanoparticles

摘要

We report the efficiency enhancement in dye-sensitized solar cells (DSSCs) using Er_(3+)/Yb_(3+)-co-doped Y~(2)O~(3) (i.e., Y~(2)O~(3):Er_(3+)/Yb_(3+)) phosphor nanoparticles, prepared by a simple and cost-effective urea-based homogeneous precipitation method, for efficient near-infrared (NIR) sunlight harvesting. Under the light excitation at a wavelength of 980?nm, the as-prepared samples exhibited strong upconversion emissions at green and red visible wavelengths. To investigate the influence of Y~(2)O~(3):Er_(3+)/Yb_(3+) nanoparticles on the photovoltaic performance of DSSCs, the phosphor nanoparticles were incorporated into titanium dioxide films to form a composite photoelectrode. For the resulting DSSCs, the increased power conversion efficiency ( PCE ) of 6.68?% was obtained mainly by the increased photocurrent of J ~(SC)?=?13.68?mA/cm_(2) due to the light harvesting enhancement via the NIR-to-visible upconversion process (cf., PCE ?=?5.94?%, J ~(SC)?=?12.74?mA/cm_(2) for the reference DSSCs without phosphor nanoparticles), thus, indicating the PCE increment ratio of ~12.4?%.