Influence of heavy atoms in β-diketone-based TADF emitters: Photophysical properties and OLED applications

Influence of heavy atoms in β-diketone-based TADF emitters: Photophysical properties and OLED applications Full article

Journal

Optical Materials
ISSN: 1873-1252 , E-ISSN: 0925-3467

Output data

Year: 2025, Volume: 168, Article number : 117470, Pages count : DOI: 10.1016/j.optmat.2025.117470

Authors

Tsorieva Alisia V. ¹ , Korshunov Vladislav M. ^2,1 , Chmovzh Timofey N. ^3,4 , Polikovskiy Trofim A. ¹ , Lypenko Dmitry A. ⁵ , Dmitriev Artem V. ⁵ , Minyaev Mikhail E. ⁴ , Aleksandrov Alexey E. ⁵ , Tameev Alexey R. ⁵ , Rakitin Oleg A. ⁴ , Taydakov Ilya V. ^4,1

Affiliations

1	P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy 1. Prospect, 119991 Moscow, Russia
2	Bauman Moscow State Technical University, 5/1 2-ya Baumanskaya Str., 105005 Moscow, Russian Federation
3	D. I. Mendeleev University of Chemical Technology, Miusskaya Ploshchad', 125047 9, Moscow, Russia
4	N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospect, 47, Moscow, 119991, Russia
5	A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky Prosp. 31, bld.4, 119071, Moscow, Russia

Thermally activated delayed fluorescence (TADF) materials offer a promising approach to enhancing the efficiency of organic light-emitting diodes (OLEDs) for next-generation ergonomic lighting applications. In this study, we investigate the influence of heavy atoms (sulfur and selenium) on the photophysical and electroluminescent properties of β-diketone-based thermally activated delayed fluorescence (TADF) emitters. Two new D-π-A-π-D dyes, featuring phenothiazine (PTZPDO) and phenoselenazine (PSeZPDO) donor units, were synthesized and thoroughly investigated. Ab-initio quantum chemistry calculations (SA-CASSCF) reveal that the introduction of sulfur and selenium significantly impacts the electronic structure, leading to distinct photoluminescence spectra compared to related systems. Interestingly, while heavy atom substitution enhances spin-orbit coupling, it also increases the singlet-triplet energy gap (ΔEST), reducing the efficiency of reverse intersystem crossing and allowing competition between TADF and triplet-state phosphorescence in PSeZPDO-doped films. We have demonstrated that PTZPDO outperforms PSeZPDO in terms of TADF emission efficiency. OLED devices based on PTZPDO exhibit bright emission with a maximum luminance of 9800 cd/m2. These findings demonstrate the potential of β-diketone-based TADF emitters with heavy atom modifications for energy-efficient OLED applications, while emphasizing the importance of optimizing molecular design to balance photophysical and device performance.

Tsorieva A.V. , Korshunov V.M. , Chmovzh T.N. , Polikovskiy T.A. , Lypenko D.A. , Dmitriev A.V. , Minyaev M.E. , Aleksandrov A.E. , Tameev A.R. , Rakitin O.A. , Taydakov I.V.
Influence of heavy atoms in β-diketone-based TADF emitters: Photophysical properties and OLED applications
Optical Materials. 2025. V.168. 117470 . DOI: 10.1016/j.optmat.2025.117470 WOS Scopus OpenAlex

≡ Web of science:	WOS:001572211300001
≡ Scopus:	2-s2.0-105015416660
≡ OpenAlex:	W4413984498