High-performance near-infrared OLEDs maximized at 925 nm and 1022 nm through interfacial energy transfer

• Published in: Nature communications Vol. 15; no. 1; pp. 4664 - 10
• Main Authors: Hung, Chieh-Ming, Wang, Sheng-Fu, Chao, Wei-Chih, Li, Jian-Liang, Chen, Bo-Han, Lu, Chih-Hsuan, Tu, Kai-Yen, Yang, Shang-Da, Hung, Wen-Yi, Chi, Yun, Chou, Pi-Tai
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 31.05.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/1019/1020/1091; 639/638/439/945; Dyes; Emitters; Energy transfer; Fluorescent dyes; Fluorescent indicators; Fullerenes; Humanities and Social Sciences; I.R. radiation; Interfacial energy; multidisciplinary; Near infrared radiation; Organic light emitting diodes; Phosphorescence; Photoluminescence; Photons; Quantum efficiency; Science; Science (multidisciplinary); Self-assembly; Spectroscopy; Transfer printing
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-49127-x

Using a transfer printing technique, we imprint a layer of a designated near-infrared fluorescent dye BTP-eC9 onto a thin layer of Pt(II) complex, both of which are capable of self-assembly. Before integration, the Pt(II) complex layer gives intense deep-red phosphorescence maximized at ~740 nm, while the BTP-eC9 layer shows fluorescence at > 900 nm. Organic light emitting diodes fabricated under the imprinted bilayer architecture harvest most of Pt(II) complex phosphorescence, which undergoes triplet-to-singlet energy transfer to the BTP-eC9 dye, resulting in high-intensity hyperfluorescence at > 900 nm. As a result, devices achieve 925 nm emission with external quantum efficiencies of 2.24% (1.94 ± 0.18%) and maximum radiance of 39.97 W sr −1 m −2 . Comprehensive morphology, spectroscopy and device analyses support the mechanism of interfacial energy transfer, which also is proved successful for BTPV-eC9 dye (1022 nm), making bright and far-reaching the prospective of hyperfluorescent OLEDs in the near-infrared region. The low photoluminescence quantum yield of near-infrared (NIR) emitters has limited their application in organic light-emitting diodes (OLEDs). Here, authors realize NIR OLEDs through interfacial energy transfer from platinum(II) complexes to a non-fullerene acceptor based on a sandwiched structure.