Benzo[4, 5]thieno-S, S-dioxide-[3, 2-b]benzofurans: synthesis, properties and application in electroluminescent devices. Issue 26 (8th June 2020)

• Record Type: Journal Article
• Authors: Ma, Weimin; Liu, Guanhao; Zhou, Lu; Li, Baolin; Wang, Ying
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 26(2020)
• Page Start: 8796
• Page End: 8803
• Publication Date: 2020-06-08
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9tc06790f
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Four organic light-emitting diodes based on the first mixed thieno- S, S -dioxide-furan acenes (BTOBFs) exhibit blue to green tunable luminescence, and respectable EQE of up to 6.49% has been achieved. Abstract : The first mixed thieno- S, S -dioxide-furan acenes (BTOBFs) were constructed by simple oxidation of benzo[4, 5]thieno-[3, 2- b ]benzofurans (BTBFs). After oxidation, the absorption and emission peaks of the compounds undergo a significant red shift, and fluorescence quantum yields ( Φ f = 0.23–0.90) are increased several to several tens of times thanks to the more rigid and more π-extended molecular backbone as well as significant intramolecular charge transfer. F-BTOBF and F, Cl-BTOBF displayed somewhat low device performance with external quantum efficiency (EQE) of 0.72–0.78% yet desirable blue emission. However, when we introduce strong electron-donating groups such as carbazolyl or triphenylamino group into BTOBFs to further tune the electronic properties, the resulting compounds 2-NPhCz-BTOBF and 2-TPA-BTOBF exhibit not only much red shift in absorption and fluorescence, but also significant improvement in hole mobility. As a result, these two compounds displayed much better device performance with respectable EQEs of 5.82–6.49%, low turn-on voltage less than 3 V and lower efficiency roll-off. Therefore, for the first time, this work reports the huge potential of mixed thieno- S, S -dioxide-furan acenes as blue to green emitters for high-performance OLEDs.