Design, synthesis and structure-property relationship of fluorenone-based derivatives for fluorescent OLEDs

Abstract

Four fluorenone-based materials were designed, prepared and characterized for organic light emitting diodes. These derivatives possess relatively high thermal stability with the 5% mass loss temperatures in the range of 271–395 °C. The fluorenone-based materials showed oxidation bands in the range of 0.77–1.11 V. Ionization potential values of the films were found to be in the range from 5.11 to 5.41 eV. The differently substituted compounds were utilized as an emitters in organic light emitting diodes. Nevertheless, the doped devices based on 90 wt% 1,3-bis(N-carbazolyl)benzene as a host material have produced orange and red electroluminescence with CIEx,y of (0.52102, 0.43609) and (0.60724, 0.38766) with a low turn on voltage of 5.08 V, maximum external quantum efficiency of 2.54%, maximum brightness efficiency of 7509.14 cd/m⁻² and maximum current and power efficiency of 15.73 cd/A⁻¹ and 8.13 lm/W⁻¹ respectively, that these results indicate that the 1,3-bis(N-carbazolyl)benzene host was matched and it is in the well agreement with emitters and select these series of compounds are an attractive approach for the extension of efficient fluorescence organic light emitting diodes.

Keywords:

• Electroluminescence
• fluorenone
• fluorescence
• OLEDs
• photophysical properties

Acknowledgments

D.G. acknowledges the Research, Development and Innovation Fund of Kaunas University of Technology (project grant No. PP59/204) for the research support. Support of the World Federation of Scientists (WFS) is gratefully acknowledged.

Additional information

Funding

This project has received funding from the Research Council of Lithuania (LMTLT), agreement No [S-LU-20-3].