Center for Physical Sciences and Technology, Savanoriu 231, LT-02300 Vilnius, Lithuania.
J Chem Phys. 2010 Oct 28;133(16):164904. doi: 10.1063/1.3493589.
The dynamics of charge carrier generation in poly(spirobifluorene-co-benzothiadiazole) was investigated by electric field-induced fluorescence quenching and differential absorption measurements. Three different time domains of carrier generation have been identified: an ultrafast phase, a subnanosecond phase, and an entire lifetime phase. The charge generation efficiencies during the first and second phases were found to be almost independent of temperature, being about 25% and 10%, respectively, at an applied electric field of 1.3×10(6) V/cm, while the generation efficiency during the third phase increases from 2% at 80 K to 10% at room temperature. The results of transient spectroscopy measurements and quantum chemical calculations suggest an intramolecular charge transfer for about 1 ps from the alkoxy-substituted fluorene side group to the benzothiadiazole subunit of the main chain. The formation and evolution of the resulting charge transfer states determine the way of charge carrier generation.
通过电致荧光猝灭和差分吸收测量研究了聚（螺二芴-共-苯并噻二唑）中的载流子产生动力学。已经确定了载流子产生的三个不同的时间域：超快相、亚纳秒相和整个寿命相。在第一和第二相期间的电荷产生效率发现几乎与温度无关，在施加的电场为 1.3×10(6)V/cm 时，分别约为 25%和 10%，而在第三相期间的产生效率从 80 K 时的 2%增加到室温时的 10%。瞬态光谱测量和量子化学计算的结果表明，大约有 1 ps 的从烷氧基取代芴侧基到主链的苯并噻二唑亚基的分子内电荷转移。所得电荷转移态的形成和演化决定了载流子产生的方式。
