Lin, Chih-Jung Lee, Wen-Ya Lu, Chien Lin, Hsiang-Wei Chen, Wen-Chang Biaxially Extended Thiophene–Fused Thiophene Conjugated Copolymers for High Performance Field Effect Transistors We report the synthesis, properties, and field-effect transistor characteristics of biaxially extended thiophene-fused thiophene conjugated copolymers, <b>P4TDTT</b> and <b>P4TTT</b>, consisting of 2′,5″-5,5‴-di(2-ethylhexyl)-[2,3′;5′,2″;4″,2‴] -quaterthiophene and fused thiophene moieties of dithieno[3,2-<i>b</i>:2′,3′-<i>d</i>]thiophene and thieno[3,2-<i>b</i>]thiophene, respectively. The effect of fused thiophene size on the molecular packing and charge transport characteristics was explored. The high boiling point solvent facilitated the formation of ordered nanofiber morphology and enhanced the optoelectronic properties. <b>P4TDTT</b> exhibited a smaller <i>d</i>-spacing and π–π stacking distance than <b>P4TTT</b> based and a denser nanofiber network. The optical band gaps of <b>P4TDTT</b> and <b>P4TTT</b> films spin-coated from trichlorobenezene (TCB) solvent were 1.84 and 1.86 eV, respectively. The highest hole mobilities of <b>P4TDTT</b> and <b>P4TTT</b> using TCB solvent were 0.610 and 0.396 cm<sup>2</sup> V<sup>–1</sup> s<sup>–1</sup>, respectively, with the on/off ratios of 10<sup>5</sup>–10<sup>6</sup>. <b>P4TDTT</b> had better charge-transporting characteristics than <b>P4TTT</b> due to the nonsymmetry side-chain arrangement and larger coplanar moieties, leading to an enhanced interchain interaction and denser molecular packing. Furthermore, these polymers showed relatively high air stability due to the relative low-lying HOMO levels. This study revealed that the biaxially extended fused ring containing conjugated polythiophenes had excellent charge-transporting characteristics for FET applications. High Performance Field Effect TransistorsWe report;biaxially;P 4TDTT;P 4TTT;denser nanofiber network;thiophene;TCB;HOMO;charge transport characteristics;moietie;Thiophene;FET 2011-12-27
    https://acs.figshare.com/articles/journal_contribution/Biaxially_Extended_Thiophene_Fused_Thiophene_Conjugated_Copolymers_for_High_Performance_Field_Effect_Transistors/2568379
10.1021/ma202017q.s001