| Improving the photoelectric conversion efficiency is a fundamental issue that must be addressed in the study of dye-sensitized solar cells (DSSCs).In this thesis, starting from the mechanism of the DSSC, by improving the preparation method of TiO2and the design and preparation of a series of rare earth complexes with photon modulation function, polyethylene glycol (PEG) was introduced into N3dye-sensitized solar cell system as a quasi-gel in order to improve the photoelectric conversion efficiency of DSSCs especially by using rare earth complexes fluorescence modulation. The works in this paper are described as follows:1.By optimizing the preparation conditions of the sol-gel method, TiO2nanocrystal was prepared as photo anode with better porosity and a larger surface area, which made it better to adsorb dyes in order to improve the photoelectric conversion efficiency of the battery. The size distribution and porosity characteristics of TiO2powder were characterized by SEM, XRD and other means in order to exclude anode interference caused by the latter introduction of the complexes by measuring the dye adsorption capacity of TiO2particle. Subsequently, the obtained nano-TiO2was coated onto the surface of the conductive glass to achieve a thin film photoanode. The results show that the particle size of nanoscale TiO2should be controlled within a certain range, too large or too small is not conducive to the adsorption of dyes.2.According to the requirements of photon modulation,5-nitro-8-hydroxy quinoline (Q5N) and dibenzoylmethane (DBM) were respectively selected to be the first ligands to coordinate with different rare earth ions. Taking into account the water of crystallization on the performance of the battery electrolyte system, after the preparation of coordination complexes with water as the second ligand, rare earth complexes with phenanthroline (Phen) as a second ligand were synthesized to replace the water in order to enhance the fluorescence effects. With the results of melting point test, FTIR, UV-Vis spectra, fluorescence spectroscopy characterization, the successful synthesis of the RE(DBM)3Phen, RE(Q5N)4Phen series of complexes was confirmed and the preliminary investigation of their fluorescence properties was carried out. 3.In order to improve the stability of the the DSSC battery systems, polyethylene glycol with different molecular weights were choosed to be the polymer matrix for quasi-gel DSSCs and the cell efficiency was compared before and after adding rare earth complexes. By measuring the voltage and current of the assembled cells with a multimeter, it reveals that the introduction of rare earth complexes can increase the initial open-circuit voltage and short-circuit current of the cells and polyethylene glycol can effectively slow down the decay rate of voltage and current with time.4.With contrasting photoelectric conversion efficiency of the cells prepared with series of rare earth complexes, Tb(Q5N)4Phen was optimized to be the most favorable one among them to enhance optimal impact on cell properties. For the DSSC system mixed with the best rare earth material, determination of the IE curves gained the photo-electrochemical properties such as the open-circuit voltage, short-circuit current, fill factor and cell efficiency etc and the photoelectric conversion efficiency (IPCE) test was combined to comparatively analyze the overall performance of a series of cells. The experimental results show that the joining of rare earth complexes promote the open-circuit voltage and the current density to0.669V and4.86mA/cm2respectively and the the fill factor reaches to40%with a cell efficiency of1.29%. By comparison and theoretical analysis of experimental results, the photon modulation of rare earth complexes affecting on DSSCs has been preliminarily clarified. |
PDF Full Text Request