Thiophene‐S,S‐dioxidized Indophenine: A Quinoid‐Type Building Block with High Electron Affinity for Constructing n‐Type Polymer Semiconductors with Narrow Band Gaps

Abstract

Three thiophene‐S,S‐dioxidized indophenine (IDTO) isomers, 3 a (E,E,E), 3 b (Z,E,E), and 3 c (Z,E,Z), were synthesized by oxidation of an indophenine compound. 3 b and 3 c could be converted into the most‐stable 3 a by heating at 110 °C. An IDTO‐containing conjugated polymer, PIDTOTT, was prepared using 3 a as a comonomer through a Stille coupling reaction, and it possesses a narrow band gap and low energy levels. In organic field effect transistors (OFETs), PIDTOTT exhibited unipolar n‐type semiconductor characteristics with unexpectedly high electron mobility (up to 0.14 cm2 V−1 s−1), despite its rather disordered chain packing.

π‐Conjugated Polymers Incorporating a Novel Planar Quinoid Building Block with Extended Delocalization and High Charge Carrier Mobility

“…However, DCM end groups have rather limited the incorporation of them into polymer backbones. Recently isatin molecules have been used as end groups for constructing quinoid structures to be utilized as conjugated backbone since they have benzene end groups …”

“…We additionally induced alignment of the polymer chains by an off‐center spinning process in order to obtain performance enhancement and uniformity of the devices. Off‐centered OFETs based on PQuT‐BT exhibited a hole mobility up to 8.09 cm 2 V −1 s −1 , which is the highest mobility among reported quinoidal polymers . The molecular packing and microstructures of the thin films were investigated using 2D grazing incidence wide‐angle X‐ray scattering (2D‐GIWAXS).…”

Two dimensional semiconducting polymers

“…As a result, TTF-TCNQ is among the early examples of organic metals and superconductors discovered so far. [2][3][4][5] The discovery of polyacetylene and its remarkably enhanced electrical conductivity after iodine-oxidization by Shirakawa, Macdiarmid, and Heeger in 1977 has opened a new era of electrically conducting 6,7 and semiconducting polymers [8][9][10][11][12][13][14][15][16][17][18] with various chemical structures. To date, advances in molecular design and synthesis have led to a large variety of semiconducting molecules and polymers for high-performance devices such as light-emitting diodes (LEDs), field-effect transistors (FETs), photovoltaic devices, and sensors.…”