The Dye-sensitized Solar Cell The Composite Photoanode Construction And Optoelectronic Properties

Solar energy, for its inexhaustible, environment friendly, low cost and without geographical restrictions, is regarded as the ideal source of energy to solve the problem of energy and environment. Dye sensitized solar cells (DSSCs) are hot research field of solar cells, which due to their low production cost and high energy conversion efficiency. Generally, DSSCs are composed of a nanocrystalline semiconductor oxide thin-film electrode, dye sensitizers, electrolytes, and a counter electrode. Thereinto, photoanodes that use as supporter of adsorbing dye and transfer photogenerated electrons have therefore been considered as one of the main factors determining the efficiency of DSSCs. In this paper, with the aim of assembling DSSCs with high photoelectron convertion efficiency and fabricating series of complex photoanodes, a great deal of effort were done to make sure its high absorbtion of dye and to enhance the effectionof transferring photogenerate electron in the interface. Combind with SPV technique, transient photovoltage and electrochemical impedance spectroscopy, we studied the transfor of photogenerated electrons in interface and to obatin the interfacial resistance of he transfor of photogenerated electrons quantitatively. The main contents of this paper as follows:1. TiO2-B NBs with different lengths are synthetized by hydrothermal process, then building the sandwich-type photoanode with P25 nanoparticles together and assembling DSSCs, which combine both the advantages of the rapid electron transport in TiO2-B NBs and the high surface area of TiO2 NPs. Obviously, the high photoelectricity convertion efficiency enhanced(7.94%). Meanwhile, we measure their photoelectricity performance by electrochemical means, and then study electron transport properties of DSSCs with different lengths of TiO2-B NBs using electrochemical impedance spectroscopy and transient photovoltage. We have also discussed the interplay between different lengths of TiO2-B NBs and photoelectric properties of DSSCs, which demonstrates that the DSSCs with longest TiO2-B NBs display the highest electron collection efficiency and the fastest interfacial electron transfer.2. Graphene and TiO2 compounds with different mass ratio were successfully synthesized by changing the mass of graphene in hydrothermal proces. Due to the excellent conductivity of graphene and high absorbtion of TiO2 nanoparticles, the compound have an advantange both in absorbing dye and improve the tansfortion of photogenerate electron effectively. The photoelectricity characterations of the assembled DSSCs device were much better than that of assembling by TiO2 nanoparticles and carbon nanotubes/TiO2. Electrochemical impedance spectroscopy was used to study the effection between the content of graphene and the photoelectricity characteration.3. TiO2 nanowires/ZnO nanorods grafted array compound photoanode was farbicated using seed growth route. Thereinto, ZnO nanorods has flower-like structure. The heteroj unctions were found between TiO2 nanowires and ZnO nanorods, which was in favour of the seperation and transfortion of photogenerate electron. Thus, the photoelecticty charactertion was improved efficiency.