Two Dibenzo[Def, Mno]chrysene-Based Polymeric Semiconductors: Surprisingly Opposite Device Performances in Field-Effect Transistors and Solar Cells

Abstract

A new series of conjugated polymers containing dibenzo[def, mno] chrysene units were successfully designed and synthesized to investigate their physical properties and device performances in field-effect transistors and photovoltaic cells. Two polymers, namely poly(4,10-bithiophene-6,12-bis(2decyltetradecyloxy)- dibezo[def, mno] chrysene) (PTTC) and poly(2,20-thiophenevinylenthiophene-4,10-[6,12-bis(2-decyltetradecyloxy)- dibenzo[def, mno] chrysene]) (PTVTC), exhibited similar light absorption, electrochemical characteristics, and theoretical electronic structures. However, they behaved very differently when used in thin-film transistors and solar cells. The PTTC polymer with two thiophene groups had better charge transport behavior, whereas the PTVTC polymer with two thiophene units connected by a vinyl group exhibited higher efficiency in bulk heterojunction photovoltaic cells. These results were discussed in terms of their nanostructural bulk morphologies established from transmission electron microscopy and two-dimensional grazing incidence wide angle X-ray scattering analyses. (C) 2016 Wiley Periodicals, Inc.