Influence of fluorine substituents on the film dielectric constant and open-circuit voltage in organic photovoltaics
作者:Pinyi Yang、Mingjian Yuan、David F. Zeigler、Scott E. Watkins、Jason A. Lee、Christine K. Luscombe
DOI:10.1039/c3tc32087a
日期:——
Conjugated polymers with fluorine substituents on their backbone have exhibited improved performance over their un-fluorinated analogues by lowering the polymer HOMO level, thereby increasing the open-circuit voltage (VOC). To further investigate how fluorine substituents improve device performance, three polymers with the same donor and acceptor co-monomers, but differing by the number of fluorine
通过降低聚合物的HOMO水平,从而增加开路电压(V OC),在其主链上具有氟取代基的共轭聚合物表现出比其未氟化类似物更高的性能。为了进一步研究氟取代基如何改善器件性能,合成了三种具有相同供体和受体共聚单体,但受体单元上氟原子数不同的聚合物。虽然单- (的HOMO能级P1F)和二氟化(P2F)聚合物基本上是相同的,增加V OC在并入OPV器件仍观察P2F。这意味着关联V OC供体聚合物的HOMO水平不足以充分解释V OC的改善。通过计算激子从测量的薄膜介电常数结合能的电荷转移,我们发现增加V OC在从去P1F到P2F激子结合能在电荷转移的降低相匹配。