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Eleven‐Membered Fused‐Ring Low Band‐Gap Polymer with Enhanced Charge Carrier Mobility and Photovoltaic Performance
Author(s) -
Li Yongxi,
Yao Kai,
Yip HinLap,
Ding FeiZhi,
Xu YunXiang,
Li Xiaosong,
Chen Yu,
Jen Alex K.Y.
Publication year - 2014
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201303953
Subject(s) - materials science , polymer , ring (chemistry) , photovoltaic system , band gap , optoelectronics , electron mobility , charge carrier , energy conversion efficiency , polymer solar cell , electrical engineering , composite material , organic chemistry , chemistry , engineering
A multi‐ring, ladder‐type low band‐gap polymer (PIDTCPDT‐DFBT) is developed to show enhanced light harvesting, charge transport, and photovoltaic performance. It possesses excellent planarity and enhanced effective conjugation length compared to the previously reported fused‐ring polymers. In order to understand the effect of extended fused‐ring on the electronic and optical properties of this polymer, a partially fused polymer PIDTT‐T‐DFBT is also synthesized for comparison. The fully rigidified polymer provides lower reorganizational energy, resulting in one order higher hole mobility than the reference polymer. The device made from PIDTCPDT‐DFBT also shows a quite promising power conversion efficiency of 6.46%. Its short‐circuit current (14.59 mA cm −2 ) is also among the highest reported for ladder‐type polymers. These results show that extending conjugation length in fused‐ring ladder polymers is an effective way to reduce band‐gap and improve charge transport for efficient photovoltaic devices.