Xu Wei-Long, Zeng Peng, Wu Bo, Zheng Fei, Zhu Furong, Smith Trevor A, Ghiggino Kenneth P, Hao Xiao-Tao
School of Physics, State Key Laboratory of Crystal Materials, Shandong University , Jinan, Shandong 250100, China.
School of Chemistry, The University of Melbourne , Parkville, Victoria 3010, Australia.
J Phys Chem Lett. 2016 May 19;7(10):1872-9. doi: 10.1021/acs.jpclett.6b00808. Epub 2016 May 6.
We report the effect of the processing solvent on the nanoscale morphology and photophysical dynamics of poly(3-butyl-thiophene) nanowires (P3BT-nw). P3BT-nw assembled in ortho-dichlorobenzene (ODCB) show higher crystallization and a longer conjugation length with increased exciton delocalization compared with those assembled in chlorobenzene (CB). It is proposed that this solvent effect is associated with the higher ordered structures formed from ODCB solution state. Charge-transfer dynamics and phase separation for P3BT-nw:PCBM blends were investigated by ultrafast fluorescence techniques. The more efficient fluorescence quenching observed in P3BT-nw:PCBM blend films processed from ODCB suggests that there is intimate contact between P3BT-nw and PCBM that facilitates charge transfer. The superior performance of organic photovoltaic devices based on P3BT-nw:PCBM bulk heterojunctions processed using ODCB is attributed to the higher crystallization of P3BT-nw, optimized phase separation, and more efficient charge transfer from P3BT-nw to PCBM.
我们报道了加工溶剂对聚（3-丁基噻吩）纳米线（P3BT-nw）的纳米级形态和光物理动力学的影响。与在氯苯（CB）中组装的相比，在邻二氯苯（ODCB）中组装的P3BT-nw表现出更高的结晶度和更长的共轭长度，且激子离域增加。据推测，这种溶剂效应与由ODCB溶液状态形成的更高有序结构有关。通过超快荧光技术研究了P3BT-nw:PCBM共混物的电荷转移动力学和相分离。在由ODCB加工的P3BT-nw:PCBM共混薄膜中观察到更有效的荧光猝灭，这表明P3BT-nw与PCBM之间存在紧密接触，有利于电荷转移。基于使用ODCB加工的P3BT-nw:PCBM本体异质结的有机光伏器件的优异性能归因于P3BT-nw的更高结晶度、优化的相分离以及从P3BT-nw到PCBM更有效的电荷转移。
