Dhital Bharat, Rao Vishal Govind, Lu H Peter
Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, USA.
Phys Chem Chem Phys. 2017 Jul 14;19(26):17216-17223. doi: 10.1039/c7cp01476g. Epub 2017 Jun 22.
Interfacial charge transfer dynamics in dye-sensitized NiO nanoparticles are being investigated for photocathodes in p-type dye-sensitized solar cells. In the photoreaction, after fast electron transfer from NiO to a molecule, the recombination of the hole in the nanoparticles with the electron in a reduced molecule plays an important role in the charge separation process and solar energy harvesting. Nevertheless, knowledge of the interfacial charge recombination (CR) rate and its mechanism is still limited due to the complex photoinduced electron and hole dynamics and lack of characterization of the inhomogeneity of the dynamics. Here, we report our work on probing interfacial charge recombination dynamics in Zn(ii)-5,10,15,20-tetra(3-carboxyphenyl)porphyrin (m-ZnTCPP) dye-sensitized NiO nanoparticles by correlating single-molecule fluorescence blinking dynamics with charge transfer dynamics using single-molecule photon-stamping spectroscopy. The correlated analyses of single-molecule fluorescence intensity, lifetime, and blinking reveal the intrinsic distribution and temporal fluctuation of interfacial charge transfer reactivity, which are closely related to site-specific molecular interactions and dynamics.
正在研究染料敏化NiO纳米颗粒中的界面电荷转移动力学，用于p型染料敏化太阳能电池中的光阴极。在光反应中，电子从NiO快速转移到分子后，纳米颗粒中的空穴与还原态分子中的电子复合在电荷分离过程和太阳能收集方面起着重要作用。然而，由于光致电子和空穴动力学复杂，且缺乏对动力学不均匀性的表征，界面电荷复合（CR）速率及其机制的相关知识仍然有限。在此，我们报告了我们的工作，即通过使用单分子光子标记光谱法将单分子荧光闪烁动力学与电荷转移动力学相关联，来探测Zn（II）-5,10,15,20-四（3-羧基苯基）卟啉（m-ZnTCPP）染料敏化NiO纳米颗粒中的界面电荷复合动力学。对单分子荧光强度、寿命和闪烁的相关分析揭示了界面电荷转移反应性的内在分布和时间波动，这与位点特异性分子相互作用和动力学密切相关。
