Modification Of TiO₂Solar Cell Photonaode By Stratified Doping And Hybridization

TiO2has been proven to be the best semiconductor electrode material due to its relatively high energy conversion efficiency and low cost. This dissertation is focused on the study of absorption layer by stratified doping and recombination with ZnO nanowires. The main content of this dissertation is as follows:1. Sb-doped TiO2and Mg-doped TiO2were successfully synthesized by hydrothermal method and prepared as working electrode according to a certain order by using a doctor-blade method. XRD results indicate that the doping has no effect on the crystal form of TiO2. The flatband potential (Eft) of Sb-Ti-Mg film was negatively shifted. A negative shift of Efb in this plot means a shift away from the redox potential, thereby an increment of Voc. Higher transfer rate of electrons in the Sb-Ti-Mg film than undoped TiO2film is confirmed by IMPS measurements, which is favorable to the higher Jsc. IMVS and EIS measurements indicate that the charge recombination increases with the sample of Mg-Ti-Sb. The optimum efficiency of8.84%was found at the sample of Sb-Ti-Mg, which gave an efficiency improved by20.4%compared with that of the cells based on pure TiO2(7.36%). 2. ZnO nanowire were post-embedded in TiO2film via a seed free low-temperature hydrothermal process. The SEM image indicates that ZnO nanowire were embedded in TiO2film. XRD results indicate that ZnO exist in the hexagonal structure. Higher transfer rate of electrons in the TiO2-ZnO nanowire hybrid film than pure TiO2film is confirmed by IMPS measurements, which is favorable to the higher Jsc. IMVS and EIS measurements indicate that the charge recombination decreases with the TiO2-ZnO nanowire hybrid film. The optimum efficiency of8.56%was found at TiO2-ZnO nanowire hybrid film, which gave an efficiency improved by16.9%compared with that of the cells based on pure TiO2(7.32%).