| Title |
New electroactive polymers with electronically isolated 4,7-diarylfluorene chromophores as positive charge transporting layer materials for OLEDs / |
| Authors |
Krucaite, Gintare ; Tavgeniene, Daiva ; Blazevicius, Dovydas ; Zhang, Baohua ; Vembris, Aivars ; Grigalevicius, Saulius |
| DOI |
10.3390/molecules26071936 |
| Full Text |
|
| Is Part of |
Molecules.. Basel : MDPI. 2021, vol. 26, iss. 7, art. no. 1936, p. 1-11.. ISSN 1420-3049 |
| Keywords [eng] |
fluorene ; hole transporting material ; ionization potential ; organic light-emitting diode ; polyether |
| Abstract [eng] |
A group of polyethers containing electroactive pendent 4,7-diarylfluorene chromophores have been prepared by the multi-step synthetic route. Full characterization of their structures has been presented. The polymeric materials represent derivatives of high thermal stability with initial thermal degradation temperatures in a range of 392-397 °C. Glass transition temperatures of the amorphous polymers range from 28 °C to 63 °C and depend on structures of the 4,7-diarylfluorene chromophores. Electron photoemission spectra of thin layers of the electroactive derivatives showed ionization potentials in the range of 5.8-6.0 eV. Hole injecting/transporting properties of the prepared polymeric materials were confirmed during formation of organic light-emitting diodes with tris(quinolin-8-olato)aluminium (Alq3) as a green emitter, which also serves as an electron transporting layer. The device using hole-transporting polymer with electronically isolated 2,7-di(4-biphenyl)fluorene chromophores demonstrated the best overall performance with low turn on voltage of 3 V, high current efficiency exceeding 1.7 cd/A, and with maximum brightness over 200 cd/m2. The organic light-emitting diode (OLED) characteristics were measured in non-optimized test devices. The efficiencies could be further improved by an optimization of device structure, formation conditions, and encapsulation of the devices. |
| Published |
Basel : MDPI |
| Type |
Journal article |
| Language |
English |
| Publication date |
2021 |
| CC license |
|
