Document Type

Journal Article

Department/Unit

Department of Physics

Title

Organic soluble indigoids derived from 3-hydroxybenzaldehyde for N-type organic field-effect transistor (OFET) applications

Abstract

Two new series of organic soluble indigoids 7-7′-dialkoxyindigoids (2a, 2b) and 4,4′-dibromo-7,7′-dialkoxyindigoids (3a, 3b) (alkoxy = n-butoxy and n-octyloxy) were synthesized starting from the inexpensive 3-hydroxybenzaldehyde. The indigoids were soluble in common organic solvents including chloroform, dichloromethane, toluene, ethyl acetate and ethers. The enhanced solubility was suggested to be a lack of intermolecular hydrogen-bonds as confirmed by single crystal X-ray diffraction analyses. It was found that intramolecular hydrogen-bonds in indigoids are crucial to the exhibition of field-effect in OFETs, while intermolecular hydrogen-bonds only caused insolubility of the indigoids. Compared to the pristine insoluble indigo (LUMO = −3.55 eV and Eg = 1.91 eV), the soluble indigoids containing electron donating alkoxy side chains at the indigoid 7 and 7′ positions were shown to have their LUMO decreased by −0.13 to −0.26 eV. Among the indigoid studied, the soluble indigoid 3a containing electron donating alkoxy side chains at the indigoid 7 and 7′ positions and bromine groups at the indigoid 4 and 4′ positions exihibited a narrowest bandgap energy with Eg = 1.66 eV. Employing the same fabrication technique and a bottom-gate-top-contact OFET configuration, the soluble indigoids were found to have electron mobility similar to and within an order of magnitude of the pristine indigo.

Publication Year

2016

Journal Title

Organic Electronics

Volume number

32

Publisher

Elsevier

First Page (page number)

258

Last Page (page number)

266

Referreed

1

DOI

10.1016/j.orgel.2016.02.035

ISSN (print)

15661199

Link to Publisher’s Edition

http://dx.doi.org/10.1016/j.orgel.2016.02.035

Keywords

OFET, Baeyer Drewson indigo synthesis, 3-Hydroxybenzaldehyde, Organic semiconductors, Organic soluble indigoids

ISSN (electronic)

18785530

This document is currently not available here.

Share

COinS