Feist Florian A, Tommaseo Giovanni, Basché Thomas
Institut für Physikalische Chemie, Johannes Gutenberg-Universität, 55099 Mainz, Germany.
Phys Rev Lett. 2007 May 18;98(20):208301. doi: 10.1103/PhysRevLett.98.208301. Epub 2007 May 15.
Fluorescence emission and excitation spectra of single poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] polymer molecules embedded in poly(methylmethacrylate) have been recorded at 1.2 K. The ubiquitous spectral diffusion causes large variations in the spectral shape and apparent linewidth in the emission spectra. Nevertheless, we find very narrow (approximately 0.1 cm(-1)) purely electronic zero-phonon lines in the excitation spectra, which are 2 orders of magnitude smaller than previous estimates of the homogeneous linewidth. These results complement the molecular description of the low energy transitions in conjugated polymers.
嵌入聚甲基丙烯酸甲酯中的单个聚[2-甲氧基-5-(2'-乙基己氧基)-1,4-亚苯基乙烯撑]聚合物分子的荧光发射光谱和激发光谱已在1.2 K下记录。普遍存在的光谱扩散导致发射光谱的光谱形状和表观线宽出现很大变化。然而，我们在激发光谱中发现了非常窄（约0.1 cm⁻¹）的纯电子零声子线，其比之前对均匀线宽的估计小2个数量级。这些结果补充了共轭聚合物中低能跃迁的分子描述。
