Department of Energy and Materials Engineering, Dongguk University, Seoul 04620, Republic of Korea.
Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
Molecules. 2022 Nov 27;27(23):8274. doi: 10.3390/molecules27238274.
In this study, we developed two thermally activated delayed fluorescence (TADF) emitters, and , to apply to organic light-emitting diodes (OLEDs). These emitters involve indolocarbazole (ICz) donor units and nicotinonitrile acceptor units with a twisted donor-acceptor-donor (D-A-D) structure for small singlet (S) and triplet (T) state energy gap (Δ) to enable efficient exciton transfer from the T to the S state. Depending on the position of the cyano-substituent, has a symmetric structure by introducing donor units at the 3,5-position of isonicotinonitrile, and has an asymmetric structure by introducing donor units at the 2,6-position of nicotinonitrile. These emitters have different properties, such as the maximum luminance () value. The of reached over 10000 cd m. The external quantum efficiency () was 14.8% for and 14.9% for , and both achieved a low turn-on voltage () of less than 3.4 eV.
在这项研究中，我们开发了两种热激活延迟荧光（TADF）发射器 和 ，将其应用于有机发光二极管（OLED）。这些发射器涉及吲哚咔唑（ICz）给体单元和烟腈受体单元，具有扭曲的给体-受体-给体（D-A-D）结构，可实现小的单重态（S）和三重态（T）态能隙（Δ），从而实现从 T 态到 S 态的高效激子转移。根据氰基取代基的位置， 通过在异烟酸腈的 3,5-位引入给体单元，具有对称结构，而 通过在烟腈的 2,6-位引入给体单元，具有不对称结构。这些发射器具有不同的性质，例如最大亮度（）值。 的 值超过了 10000 cd/m²。对于 和 ，外量子效率（）分别为 14.8%和 14.9%，两者均实现了低于 3.4 eV 的低开启电压（）。
