文献类型：期刊文献

英文题名：Competition between host aggregates and isolated guest chromophores in trapping excitons in polybenzazole copolymers and blends

作者：Wang, Shanfeng[1,2]; Chen, Yan[1]; Zhuang, Qixin[1]; Li, Xinxin[1,2]; Wu, Pingping[1]; Han, Zhewen[1]

机构：[1]E China Univ Sci & Technol, Key Lab Ultrafine Mat, Minist Educ, Sch Mat Sci & Engn, Shanghai 200237, Peoples R China;[2]Mayo Clin, Dept Orthoped Surg, Rochester, MN 55905 USA;[3]Mayo Clin, Dept Biomed Engn, Rochester, MN 55905 USA

年份：2006

卷号：207

期号：24

起止页码：2336

外文期刊名：MACROMOLECULAR CHEMISTRY AND PHYSICS

收录：;EI(收录号：20070210358820);WOS:【SCI-EXPANDED(收录号:WOS:000243389200008)】；

语种：英文

外文关键词：conjugated polymers; energy transfer; photophysics; poly(p-phenylene benzobisoxazole); poly(2,5-thienylbenzobisoxazole)

摘要：Host-guest systems have been prepared using the blends and copolymers consisting of the host molecule poly (p-phenylene benzobisoxazole) (PBO) with a higher bandgap of 2.93 eV and the guest molecule poly(2.5-thienylbenzobisoxazole) (PBOT) with a lower bandgap of 2.7 eV. These systems have been investigated using photoluminescence (PL) spectra and time-resolved PL decay dynamics. Both PBOT-PBO copolymers and PBOT/PBO blends with the PBOT compositions less than 20% demonstrate higher intensities and narrower bandwiths in solid-state emission compared to that of PBOT, as well as larger fractions of the shorter lifetime component in PL decay dynamics. A general scheme on intrachain and interchain exciton migration and trapping mechanism has been proposed to interpret the phenomena in both solutions and thin films. Particularly, a competition in trapping exciton between PBO aggregates and isolated PBOT chromophores has been revealed.