FENG Shile ¹, HUANG Mengling ¹, SHI Wei ^{1, 2}, ZENG Tao ^{1, 3}, CHEN Yunxia ^{1, 2}, SU Xiaoli ¹
(1. Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China; 2. National Engineering Research Center for Domestic & Building Ceramics, Jingdezhen 333001, Jiangxi, China; 3. State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, Hubei, China)

Abstract: The as-received titanium (IV) isopropoxide was used as the Ti source, zinc acetate dihydrate as the dopant, ethanolamine as the ligand, and absolute alcohol as the solvent, and all of them were mixed homogeneously at the well-established ratio to form a transparent reaction precursor. Then, the reaction precursor was crystallized into the TiO₂ nanocrystals (NCs) with different content of Zn dopants that can serve as the photoanode materials in N719 dye-sensitized solar cells by the hydrothermal vapor induced-crystallization strategy. The effect of Zn-doping content on the performance of the sensitized photovoltaics was studied. Results indicated that the best power conversion efficiency (PCE-8.18%) of the sensitized photovoltaics could be achieved with 3 atom% dopants. However, the PCE of the sensitized photovoltaics would be deteriorated along with the further increasing of Zn-doping content, and the relevant results revealed that the short current density (Jsc) and open circuit voltage (Voc) for the sensitized photovoltaics could be improved by adding adequate Zn-dopants thanks to their unique role in enlarging the specific area through the decrease of the TiO₂ NCs’ size and the rise of the corresponding Fermi-level in the photoanode at the same time, whereas the excess Zn dopants would create the notorious defects in the photoanodes to bring about dramatic recombination of photo-generated carriers, which in turn could weaken the performance.

Key words: Zn-doped TiO₂; PCE; fermi level; specific area; recombination