1 research outputs found
<i>S</i>,<i>N</i>‑Heteroacene-Based Copolymers for Highly Efficient Organic Field Effect Transistors and Organic Solar Cells: Critical Impact of Aromatic Subunits in the Ladder π‑System
Three novel donor–acceptor
alternating polymers containing ladder-type pentacyclic heteroacenes
(<b>PBo</b>, <b>PBi</b>, and <b>PT</b>) are synthesized,
characterized, and further applied to organic field effect transistors
(OFETs) and polymer solar cells. Significant aspects of quinoidal
characters, electrochemical properties, optical absorption, frontier
orbitals, backbone coplanarity, molecular orientation, charge carrier
mobilities, morphology discrepancies, and the corresponding device
performances are notably different with various heteroarenes. <b>PT</b> exhibits a stronger quinoidal mesomeric structure, linear
and coplanar conformation, smooth surface morphology, and better bimodal
crystalline structures, which is beneficial to extend the π-conjugation
and promotes charge transport via 3-D transport pathways and in consequence
improves overall device performances. Organic photovoltaics based
on the <b>PT</b> polymer achieve a power conversion efficiency
of 6.04% along with a high short-circuit current density (<i>J</i><sub>SC</sub>) of 14.68 mA cm<sup>–2</sup>, and
a high hole mobility of 0.1 cm<sup>2</sup> V<sup>–1</sup> s<sup>–1</sup> is fulfilled in an OFET, which is superior to those
of its counterparts, <b>PBi</b> and <b>PBo</b>