Mallesham, G. and Balaiah, S. and Reddy, M. Ananth and Sridhar, B and Singh, Punita and Srivastava, Ritu and Bhanuprakash, K and Rao, V. Jayathirtha (2014) Design and synthesis of novel anthracene derivatives as n-type emitters for electroluminescent devices: a combined experimental and DFT study. Photochemical & Photobiological Sciences Photochemical and Photobiological Sciences, 13 (2). pp. 342-357. ISSN 1474-905X

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Abstract

Six novel anthracene-oxadiazole derivatives, 4a (2-(4-(anthracen-9-yl)phenyl)-5-p-tolyl-1,3,4-oxadiazole), 4b (2-(4-(anthracen-9-yl)phenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), 4c (2-(4-(anthracen-9-yl)phenyl)-5-(4-methoxyphenyl)-1,3,4-oxadiazole), 8a (2-(4-(anthracen-9-yl)phenyl)-5-m-tolyl-1,3,4-oxadiazole), 8b (2-(3-(anthracen-9-yl)phenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole) and 8c (2-(3-(anthracen-9-yl)phenyl)-5-(3,4,5-trimethoxyphenyl)-1,3,4-oxadiazole) have been synthesized and characterized for use as emitters in organic light emitting devices (OLEDs). They show good thermal stability (T-d, 297-364 degrees C) and glass transition temperatures (T-g) in the range of 82-98 degrees C, as seen from the thermo gravimetric analysis and differential scanning calorimetric studies. The solvatochromism phenomenon and electrochemical properties have been studied in detail using UV-Vis absorption, fluorescence spectroscopy and cyclic voltammetry. TD-DFT calculations have been carried out to understand the electrochemical and photophysical properties. The spatial structures of 4b and 8c are further confirmed by X-ray diffraction analysis. Un-optimized non-doped electroluminescent devices were fabricated using these anthracene derivatives as emitters with the following device configuration: ITO (120 nm)/alpha-NPD (30 nm)/4a-4c or 8a-8c (35 nm)/BCP (6 nm)/Alq(3) (28 nm)/LiF (1 nm)/Al (150 nm). Among all the six compounds, 8a displays the maximum brightness of 1728 cd m(-2) and current efficiency 0.89 cd A(-1). Furthermore, as an electron transporter, 8a exhibited superior performance (current efficiency is 11.7 cd A(-1)) than the device using standard Alq(3) (current efficiency is 8.69 cd A(-1)), demonstrating its high potential for employment in OLEDs. These results indicate that the new anthracene-oxadiazole derivatives could play an important role in the development of OLEDs.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/S RSC.
Subjects:	Biochemistry & Molecular Biology Biophysics Chemistry
Divisions:	UNSPECIFIED
Depositing User:	Dr. Rajpal Walke
Date Deposited:	21 Sep 2015 06:32
Last Modified:	21 Sep 2015 06:32
URI:	http://npl.csircentral.net/id/eprint/1229

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