Low band-gap copolymers derived from fluorinated isoindigo and dithienosilole: synthesis, properties and photovoltaic applications
Low band-gap copolymers derived from fluorinated isoindigo and dithienosilole: synthesis, properties and photovoltaic applications
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DOI：
10.1039/c4py00273c
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发表时间：
2014-07
影响因子：
4.6
通讯作者：
Zhenguo Wang;Jie Zhao;Ying Li;Q. Peng
中科院分区：
文献类型：
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作者：
Zhenguo Wang;Jie Zhao;Ying Li;Q. Peng
一种低带隙共聚物，PDTS-FID，包含交替二噻吩硅（DTS）供体嵌段和氟化异靛蓝（FID）单元，以及它的非氟化对偶，PDTS-ID，已被合成并表征用于光伏应用。与PDTS-ID相比，其氟化产物PDTS-FID具有更宽、更强的吸收、更低的HOMO和LUMO能级以及更高的空穴迁移率，从而提高了开路电压（Voc）、短路电流密度（Jsc）、填充因子（FF）和功率转换效率（PCE）。积极影响归因于氟化等靛蓝嵌段有利于线性和平面构象，使相关共聚物的骨架填充更好，理论计算（DFT）也证实了这一点。制备了常规装置和倒置装置，并对其进行了评价，以探索所得共聚物的光伏性能。以PDTS-FID为供体材料的倒置聚合物太阳能电池（PSC）的PCE性能为5.79%，Voc为0.84 V， Jsc为10.77 mA cm−2，FF为0.64。这些低带隙共聚物有望成为聚氯乙烯中应用的有前途的供体材料。
A low band-gap copolymer, PDTS-FID, containing alternating dithienosilole (DTS) donor blocks and fluorinated isoindigo (FID) units, and its non-fluorinated counterpart, PDTS-ID, have been synthesized and characterized for photovoltaic applications. Compared to PDTS-ID, its fluorinated counterpart, PDTS-FID, exhibits broader and stronger absorption, lower-lying HOMO and LUMO energy levels, and higher hole mobility, resulting in an improved open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF) and power conversion efficiency (PCE). The positive effects were attributed to the fluorinated isoindigo block which favored a linear and planar conformation, giving rise to better backbone packing of the related copolymer, which was also confirmed by theoretical calculations (DFT). The conventional and inverted devices were fabricated and evaluated to explore the photovoltaic properties of the resulting copolymers. The best performance of 5.79% PCE was obtained from an inverted polymer solar cell (PSC) using PDTS-FID as the donor material, with a Voc of 0.84 V, a Jsc of 10.77 mA cm−2 and a FF of 0.64. These low band-gap copolymers could be expected to be promising donor materials for application in PSCs.