Organic Semiconducting Materials Based on Ladder-Type Aromatics for Energy and Electronic Applications

Abstract：Ladder-type aromatics usually have a planar structure which can be constructed by linking different aromatic units such as benzene or thiophene via sp3 bridging atoms. In this work, both p-type (hole-transporting) and n-type (electron-transporting) semiconducting materials are developed by using various ladder-type aromatics as electron-donating units [1-7]. The bandgaps and carrier transporting properties of the semiconducting materials are easily tuned by introducing different heteroatoms (sulfur, nitrogen) in the ladder-type fused-ring system. As p-type semiconductors in the photovoltaic application, ladder-type-aromatics-based copolymers exhibit a best power conversion efficiency (PCE) of 9.51% [3]. As n-type semiconductors in the photovoltaic application, ladder-type-aromatics-based non-fullerene acceptors show a best PCE of 11.28% and a minimal energy loss of 0.50 eV [4]. The ladder-type-aromatics-based copolymers are also useful in electronic applications such as organic field-effect transistors (OFETs) and related pressure sensors [5-7]. With the signal amplification induced by OFET, the best-performance flexible pressure sensors deliver a high sensitivity of 452.7 kPa-1 at a low-operating voltage of 0.7 V.