Saavedra Becerril Valeria, Sundin Elin, Mapar Mokhtar, Abrahamsson Maria
Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Göteborg, Sweden.
Department of Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden.
Phys Chem Chem Phys. 2017 Aug 30;19(34):22684-22690. doi: 10.1039/c7cp04486k.
A simple method for the preparation of patterned dye-sensitized SnO-TiO thin films, designed to prolong the lifetime of the interfacial charge separated state is presented. Using microfluidic technology, the thin films were sensitized with the organic sensitizer D35 such that they contain SnO-TiO areas with dye and SnO dye-free areas at which injected electrons can be accumulated. Single wavelength transient absorption spectroscopy confirmed significantly extended charge separation lifetime at the dye-semiconductor interface. Sufficiently high density of injected electrons results in substantial decrease of charge recombination rate constants (k); a factor of ∼50 compared to dye-sensitized TiO thin films and a factor of ∼2000 compared to dye-sensitized SnO thin films. Furthermore, the potential of this approach was confirmed by photoinduced conduction band mediated electron transfer from the dye to a model electron acceptor, Co protoporphyrin IX, which was adsorbed to the SnO-only regions.
本文提出了一种制备图案化染料敏化SnO-TiO薄膜的简单方法，该方法旨在延长界面电荷分离态的寿命。利用微流控技术，用有机敏化剂D35对薄膜进行敏化，使其包含有染料的SnO-TiO区域和无染料的SnO区域，注入的电子可以在无染料区域积累。单波长瞬态吸收光谱证实了染料-半导体界面处电荷分离寿命的显著延长。注入电子的足够高的密度导致电荷复合速率常数（k）大幅降低；与染料敏化TiO薄膜相比约为50倍，与染料敏化SnO薄膜相比约为2000倍。此外，通过光诱导导带介导的从染料到吸附在仅含SnO区域的模型电子受体原卟啉钴IX的电子转移，证实了该方法的潜力。
