Zigzag‐Elongated Fused π‐Electronic Core: A Molecular Design Strategy to Maximize Charge‐Carrier Mobility

Abstract

Printed and flexible electronics requires solution‐processable organic semiconductors with a carrier mobility (μ) of ≈10 cm2 V−1 s−1 as well as high chemical and thermal durability. In this study, chryseno[2,1‐b:8,7‐b′]dithiophene (ChDT) and its derivatives, which have a zigzag‐elongated fused π‐electronic core (π‐core) and a peculiar highest occupied molecular orbital (HOMO) configuration, are reported as materials with conceptually new semiconducting π‐cores. ChDT and its derivatives are prepared by a versatile synthetic procedure. A comprehensive investigation reveals that the ChDT π‐core exhibits increasing structural stability in the bulk crystal phase, and that it is unaffected by a variation of the transfer integral, induced by the perpetual molecular motion of organic materials owing to the combination of its molecular shape and its particular HOMO configuration. Notably, ChDT derivatives exhibit excellent chemical and thermal stability, high charge‐carrier mobility under ambient conditions (μ ≤ 10 cm2 V−1 s−1), and a crystal phase that is highly stable, even at temperatures above 250 °C.

Molecular Semiconductors for Logic Operations: Dead‐End or Bright Future?

“…Okamoto et al have introduced the concept of V‐ and N‐shaped semiconductors in an effort to reduce lateral displacements along the longest axis of π‐systems that are particularly detrimental to charge transport . Compounds 12–15 are representative examples . Other thienoacenes, such as 8–11 and 16 , are also, to some extent, N shaped .…”

“…Recently, chryseno[2,1‐ b :8,7‐ b ′]dithiophene (ChDT) derivatives 14 , which have zigzag‐elongated fused π‐cores, has been reported. The highest mobility value reached 10 cm 2 V −1 s −1 . The V‐shaped dioctyl‐substituted thieno[3,2‐f:4,5‐f′]bis[1]benzothiophene (syn‐TBBT‐8) 15 synthesized by Yasuda et al shows a mobility of 10 cm 2 V −−1 s −1 .…”

Facile synthesis of picenes incorporating imide moieties at both edges of the molecule and their application to n-channel field-effect transistors

“…[7][8][9] Thus, organic molecules achieving a hole mobility exceeding 10 cm 2 V À1 cm À1 have been reported, e.g., [1]benzothieno [3,2-b] [1]benzothiophene (BTBT) 10 and related thiophene-fused polycyclic aromatics. [11][12][13][14][15] The present authors have investigated phenacene-based organic FETs to demonstrate that phenacenes are promising p-type semiconductors. 16,17 Namely, single-crystal FETs of [9]phenacene and thin-lm FETs of 3,10-ditetradecylpicene ((C 14 H 29 ) 2 -picene) displayed carrier mobility (m) as high as 18 and 21 cm 2 V À1 cm À1 , respectively.…”

Synthesis of Dinaphtho[2,3-d:2’,3’-d’]anthra[1,2-b:5,6-b’]dithiophene (DNADT) Derivatives: Effect of Alkyl Chains on Transistor Properties

“…Organic field-effect transistors (OFETs) using thin films and single crystals of π-extended thienoacene and thienophenacene molecules have attracted much attention as the key elements for realizing future ubiquitous electronics because they are known to display excellent hole transport properties [1][2][3][4][5]. In terms of single crystal OFETs, rubrene has provided excellent FET characteristics with carrier mobility (µ) as high as 40 cm 2 V -1 s -1 [6], but the rubrene molecule has scarcely been available for thin-film FETs, i.e., very few rubrene thin-film FETs have been operated [7].…”