Fast exciton diffusion in chiral stacks of conjugated p-phenylene vinylene oligomers -: art. no. 045203
Fast exciton diffusion in chiral stacks of conjugated p-phenylene vinylene oligomers -: art. no. 045203
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DOI：
10.1103/physrevb.68.045203
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发表时间：
2003-07-15
影响因子：
3.7
通讯作者：
Phillips, RT
中科院分区：
文献类型：
--
作者：
Herz, LM;Daniel, C;Phillips, RT
研究了具有氢键官能团的共轭对苯基乙烯分子手性叠层的超快光激发动力学。结果表明，在溶液中，分子之间的π - π相互作用导致激子沿组件的堆叠轴快速扩散。通过光致发光偏振各向异性的时间分辨测量，发现这些组件的手性导致沿堆栈传播的激子偶极矩的旋转。在分子堆中观察到的激子扩散和能量弛豫动力学与在共轭聚合物薄膜中发现的非常相似。此外，通过改变周围溶剂的温度，可以通过显着降低激子的扩散率来证明堆叠可以可逆地解离。
The ultrafast dynamics of photoexcitations have been studied in chiral stacks of conjugated p-phenylene vinylene molecules functionalized with hydrogen-bonding groups. The results indicate that in solution, pi-pi interactions between the molecules give rise to fast exciton diffusion along the stacking axis of the assemblies. The chiral nature of the assemblies is found to cause a rotation of the dipole moment of excitons propagating along the stacks as indicated by time-resolved measurements of the photoluminescence polarization anisotropy. The observed exciton diffusion and energy relaxation dynamics in the molecular stacks are shown to be very similar to those found in conjugated polymer films. Moreover, it is demonstrated that through changes in the temperature of the surrounding solvent, the stacks can be dissociated reversibly as shown by a marked reduction in the diffusivity of excitons.