Preparation And Optimization Of The Photoanode For Sensitized Solar Cells

Dye sensitized solar cells (DSSC) have been gradually on its way tocommercial usage due to their low production cost, simple technique andhigh power conversion efficiency. Improving the photoelectric conversionefficiency is still crucial for DSSC’s full commercialization. Poroustitanium dioxide (TiO2) photoanode is a stable material, which can onlyabsorb the ultraviolet with wavelength less than387nm, while its surfaceadsorbate dye N719is one of the best dyes that only absorb visible light inthe wavelength range of300-800nm. That is to say, most of the infraredand ultraviolet irradiations of sunlight cannot be utilized. Therefore, if theinfrared and ultraviolet irradiations can be absorbed by the DSSC, itsphotoelectric conversion efficiency will be improved a lot.In this thesis, TiO2nanoparticles were prepared by the hydrolysis ofTiCl4and characterized by XRD, SEM, BET. And some preparationtechnologies of the DSSC were also developed.Thermoelectric material Bi+2Te3and luminescent material Gd2O3:Tb3 were prepared by solvent thermal method and homogeneous precipitationmethod. They were characterized and analyzed by XRD, SEM, TEM, EDSand BET. Bi2Te3and Gd2O3:Tb3+were added separately into the lightabsorption layer of DSSC, and the doping concentrations were optimized.When adding Gd2O3:Tb3+, we also adjusted the percentage of Gd and Tbatoms to optimize the power conversion efficiency of DSSC. The resultsare as follows.(1) When the weight percentage of Bi2Te3nanoparticls in lightabsorption layer is0.89%or so, the best solar conversion efficiency of theDSSC with Bi2Te3doped reaches4.78%under illumination of simulatedAM1.5solar light, which enhances8.39%as compared to the traditionalDSSC without any addition of Bi2Te3.(2) When Gd32O3:Tb+was added into the light absorption layer withGd and Ti atomic ratio of10:100, the best conversion efficiency of theDSSC with5%Gd2O3:Tb3+doped is5.48%under illumination of simulatedAM1.5solar light, enhancing24.3%as compared to the traditional DSSCwithout any addition of Gd2O3:Tb3+.(3) The luminescent particles Gd2O3:Tb3+with the molar percent of Tbbeing5%,10%and15%are added into the light absorption layer of DSSC,respectively, and the atomic ratio of Gd to Ti is fixed at10:100for eachspecimen. The experiment results show that when Gd2O3:Tb3+with the molar percent of Tb being10%is added into the DSSC, the best conversionefficiency of the DSSC is5.90%under illumination of simulated AM1.5solar light, enhancing33.79%as compared to the traditional DSSC withoutany addition.