Donker Harry, van Hoek Arie, van Schaik Willem, Koehorst Rob B M, Yatskou Mikalai M, Schaafsma Tjeerd J
Laboratory for Biophysics, Department of Agrotechnology and Food Sciences, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands.
J Phys Chem B. 2005 Sep 15;109(36):17038-46. doi: 10.1021/jp058055g.
Exciton diffusion has been studied in 5-25-nm-thick films of zinc tetra-(p-octylphenyl)-porphyrin (ZnTOPP) spin-coated onto quartz slides by intentional doping with quenchers using steady-state as well as time-resolved fluorescence spectroscopy. The fluorescence spectra of the films are very similar to those of solutions, indicating emission from localized exciton states. From the dependence of the fluorescence quenching on the quencher concentration and fluorescence lifetime measurements, the exciton diffusion can be concluded to be quasi-one-dimensional with an exciton diffusion length of 9 +/- 3 nm and an intrastack energy-transfer rate constant of 10(11)-10(12) s(-1). From fluorescence anisotropy decay measurements, we conclude that neighboring stacks aggregate in a herringbone structure, forming ordered domains that are randomly oriented in the substrate plane. These measurements indicate an interstack energy-transfer rate constant of (7 +/- 2) x 10(10) s(-1).
通过使用稳态以及时间分辨荧光光谱法，通过有意掺杂猝灭剂，对旋涂在石英载玻片上的5 - 25纳米厚的四（对辛基苯基）锌卟啉（ZnTOPP）薄膜中的激子扩散进行了研究。薄膜的荧光光谱与溶液的荧光光谱非常相似，表明是从局域激子态发射的。从荧光猝灭对猝灭剂浓度的依赖性以及荧光寿命测量结果可以得出，激子扩散为准一维的，激子扩散长度为9±3纳米，叠层内能量转移速率常数为10(11)-10(12) s(-1)。从荧光各向异性衰减测量结果可以得出，相邻的叠层以人字形结构聚集，形成在基底平面内随机取向的有序域。这些测量结果表明层间能量转移速率常数为(7±2)×10(10) s(-1)。
