【摘要】 苯环取代聚乙炔是一类具有简并基态的发光聚合物 .利用扩展的Su Schrieffer Heeger模型 ,研究了这类聚合物链中的孤子、极化子等元激发特性 .结果表明 :由于苯环与聚乙炔主链间的强π 电子耦合 ,苯环取代抑制了聚乙炔主链的二聚化 ,减小了导带与价带之间的能隙 ;因此取代聚乙炔中的元激发具有较小的激发能 ,同时具有更大的相干长度 .尽管苯基取代对元激发有很大的影响 ,但是非取代聚乙炔中元激发的基本物理规律依然成立 ,表明这些元激发的基本特性不受取代基团的影响更多还原

【Abstract】 Phenyl substituted polyacetylene is a kind of photo emissive conjugated polymers, which have a degenerate ground state. By using an extended Su Schrieffer Heeger model, we investigate the elementary excitations, such as soliton and polaron, in these polymer chains. It is found that the phenyl substitution will suppress the dimerization in the polyacetylene chain and then the band gap due to the strong π electron coupling between the phenyl and polyacetylene chain, so that there will be a smaller creation energy and a longer coherent length for these excitations. In spite of the influence of the phenyl substitution on the elementary excitations, the basic characters of these excitations are unchanged.更多还原