State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 2699 Qianjin Avenue, Changchun, 130012 (P.R. China).
Angew Chem Int Ed Engl. 2015 Oct 26;54(44):13068-72. doi: 10.1002/anie.201506687. Epub 2015 Sep 7.
Significant efforts have been made to develop high-efficiency organic light-emitting diodes (OLEDs) employing thermally activated delayed fluorescence (TADF) emitters with blue, green, yellow, and orange-red colors. However, efficient TADF materials with colors ranging from red, to deep-red, to near-infrared (NIR) have been rarely reported owing to the difficulty in molecular design. Herein, we report the first NIR TADF molecule TPA-DCPP (TPA=triphenylamine; DCPP=2,3-dicyanopyrazino phenanthrene) which has a small singlet-triplet splitting (ΔEST ) of 0.13 eV. Its nondoped OLED device exhibits a maximum external quantum efficiency (EQE) of 2.1 % with a Commission International de L'Éclairage (CIE) coordinate of (0.70, 0.29). Moreover, an extremely high EQE of nearly 10 % with an emission band at λ=668 nm has been achieved in the doped device, which is comparable to the most-efficient deep-red/NIR phosphorescent OLEDs with similar electroluminescent spectra.
人们已经做出了巨大的努力来开发高效率的有机发光二极管（OLED），采用热激活延迟荧光（TADF）发射体，具有蓝色、绿色、黄色和橙红色。然而，由于分子设计的困难，很少有报道具有从红色到深红色到近红外（NIR）颜色的高效 TADF 材料。在此，我们报告了第一个 NIR TADF 分子 TPA-DCPP（TPA=三苯胺；DCPP=2,3-二氰基吡嗪并菲），其单重态-三重态分裂（ΔEST）很小，为 0.13 eV。其非掺杂 OLED 器件的最大外量子效率（EQE）为 2.1%，色坐标为（0.70,0.29）。此外，掺杂器件中实现了极高达近 10%的 EQE 和 λ=668nm 的发射带，与具有相似电致发光光谱的最有效的深红色/NIR 磷光 OLED 相当。
