Twisted olefinic building blocks for low bandgap polymers in solar cells and ambipolar field-effect transistors
A series of polymers based on 8,8′-biindeno[2,1-b]thiophenylidene for use in photovoltaic devices and field-effect transistors are reported. These structurally twisted olefins are effective building blocks for preparation of low bandgap polymers with optical bandgaps of 1.2–1.5 eV. Device performance, such as Voc and Jsc, in solar cell devices could be successfully modulated by incorporation of a variety of comonomers. Ambipolar properties in field-effect transistors using Au electrodes were also studied, with PtBTPDPP exhibiting balanced charge transport properties with hole and electron mobilities of 0.09 and 0.12 cm2·V−1·s−1, respectively.