The Investigation On Oxide Nanocrystall Materials For Dye-Sensitized Solar Cells

Recently, renewable energy has attracted a great deal of attention for the energyshortage become increasing prominent. Dye-sensitized solar cells （DSCs） are one of themost competitive third-generation solar cells due to sevral advantages, including low-cost,lightweight, and scalable production. This thesis aims to improve the stability andefficiency of DSCs.The ustage of solid-state hole-transporting materials （HTM） instead of liquidelectrolyte to produce solid-state dye-sensitized solar cells （SSDSCs） can improve thedevices’ stability. In the first part of this thesis an ordered TiO2nanorod arrays on the topof a transparent conductive glass substrate covered with a thin TiO2compact layer isintroduced. SSDSCs are fabricated using these structured TiO2films sensitized with C106dye as a photoanode and spiro-MeOTAD as the organic HTM. Photovoltaic powerconversion efficiency of2.9%is obtained at full sunlight intensity.Tandem dye-sensitized solar cells （tandem DSCs） can improve the voltage and thetheoretical efficiency of the DSCs. The second part of this thesis focuses on the researchof p-type semiconductors used as the charge collection materials in p-type dye-sensitizedsolar cells （p-DSCs）, which is a limitation for the development of tandem DSCs. K-dopedZnO nanoparticles with size of30-40nm are synthesized with hydrothermal method.Photovoltaic power conversion efficiency of0.012%is obtained at full sunlight intensityfor p-DSC based on the K-doped ZnO nanoparticles in combination with theCoumarin343sensitizer. A further study with transient photovoltage/photocurrent decaymeasurement shows an appreciate hole diffusion coefficient (¹0^-6cm²/s) for the K-dopedZnO nanoparticles. Compared to the widely used NiO nanoparticles，this advantage iscrucial for further improving the efficiency of p-type DSCs.