Issue 43, 2020

“Heavy-atom effects” in the parent [1]benzochalcogenopheno[3,2-b][1]benzochalcogenophene system

Abstract

[1]Benzochalcogenopheno[3,2-b][1]benzochalcogenophenes (BXBXs) have been the key π-conjugated core structures in the development of superior organic semiconductors for organic field-effect transistors (OFETs). The semiconducting properties of parent BXBXs, however, have not been well examined. In this work, we focus on the parent system and investigate the effect of different chalcogen atoms, i.e., sulphur, selenium or tellurium atoms, in the BXBX core on molecular electronic properties, crystal structures, intermolecular interactions, solid-state electronic structures, and carrier transport properties. Replacing the sulphur atoms in [1]benzothieno[3,2-b][1]benzothiophene (BTBT) with selenium atoms marginally changes the molecular properties and the intermolecular interactions, thus resulting in similar herringbone packing structures in the solid state. The carrier mobilities of single-crystal (SC)-OFETs are higher for [1]benzoselenopheno[3,2-b][1]benzoselenophene (BSBS) than those for BTBT, which can be understood by the increase in the intermolecular electronic coupling in BSBS, originating from the larger atomic radius and more diffused electron cloud of selenium atoms than sulphur atoms. On the other hand, the packing structure of [1]benzotelluropheno[3,2-b][1]benzotellurophene (BTeBTe) is determined to be a dimeric herringbone structure. The crystal structure of BTeBTe being strikingly different from those of BTBT and BSBS can be explained by a drastic change in the intermolecular interaction in the solid state. Furthermore, the BTeBTe-based SC-OFETs do not show transistor response. To elucidate these unexpected results, various experimental and theoretical approaches, e.g., evaluation of ionization potentials and band calculations, are examined. Through these approaches, a comprehensive view of the parent BXBX system is given, and also both the pros and cons of incorporation of heavy chalcogen atoms, positive and negative “heavy-atom effects”, in developing organic semiconductors are discussed.

Graphical abstract: “Heavy-atom effects” in the parent [1]benzochalcogenopheno[3,2-b][1]benzochalcogenophene system

Associated articles

Supplementary files

Article information

Article type
Paper
Submitted
19 Marts 2020
Accepted
11 Maijs 2020
First published
11 Maijs 2020

J. Mater. Chem. C, 2020,8, 15119-15127

“Heavy-atom effects” in the parent [1]benzochalcogenopheno[3,2-b][1]benzochalcogenophene system

C. Wang, M. Abbas, G. Wantz, K. Kawabata and K. Takimiya, J. Mater. Chem. C, 2020, 8, 15119 DOI: 10.1039/D0TC01408G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements