Carbazole鈥揚henylbenzotriazole Copolymers as Absorber Material in Organic Solar Cells

详细信息    查看全文

• 作者：Michael F. G. Klein ; Felix M. Pasker ; Stefan Kowarik ; Dominik Landerer ; Marina Pfaff ; Matthias Isen ; Dagmar Gerthsen ; Uli Lemmer ; Sigurd H枚ger ; Alexander Colsmann
• 刊名：Macromolecules
• 出版年：2013
• 出版时间：May 28, 2013
• 年：2013
• 卷：46
• 期：10
• 页码：3870-3878
• 全文大小：494K
• 年卷期：v.46,no.10(May 28, 2013)
• ISSN：1520-5835

文摘

An alternating copolymer comprising a 2,7-functionalized carbazole donor and a 2-phenyl-2H-benzotriazole acceptor with an octyldodecyloxy substituent was synthesized. The polymer was blended with [6,6]-phenyl C₇₁-butyric acid methyl ester (PC₇₁BM) and incorporated as absorber layer into solution processed organic solar cells. By adding the processing additive 1,8-diiodooctane (DIO) to the host solvent 1,2-dichlorobenzene (DCB), the solar cell fill factor increased to remarkable 70% and the power conversion efficiency approached 4.6%. Low-energy scanning transmission electron microscopy (low-keV STEM) investigations indicated a finer bulk morphology of the active layer upon deposition from DCB:DIO. Further, the low-energy shoulder of the absorption spectrum was enhanced, indicating stronger polymer aggregation. According to external quantum efficiency measurements, the enhanced absorption also promoted better photon harvesting. Grazing incidence X-ray diffraction experiments revealed face-on polymer aggregates being beneficial for the vertical hole transport.