Carbene-metal-amide materials design for application in deep-blue and near-IR energy efficient OLEDs Alexander Romanov 1 , Alexander Brannan 1 , Qinying Gu 2 , Hwan-Hee Cho 2 , Florian Chotard 3 , Antti-Pekka M. Reponen 2 , Neil Greenham 2 , Manfred Bochmann 3 1 Department of Chemistry, University of Manchester, Manchester, M13 9PL, UK. E-mail: alexander.romanov@manchester.ac.uk 2 Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HF, UK 3 School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK Two-coordinate coinage metal complexes with linear geometry L–Metal–X (L = carbene and X = anionic ligand) have recently emerged as a new class of strongly photoemissive materials – Carbene Metal Amides (CMA). 1-5 Their effectiveness is based on a combination of the ligands with complementary donor and acceptor properties resulting in unity luminescence quantum yields and short excited state lifetimes at room temperature (<1 μs). Varied temperature experiments support the thermally activated delayed fluorescence (TADF) process with very low activation energy barriers (20–150 meV). Although the coinage metal atoms make only small contributions to HOMOs and LUMOs, the sufficient spin-orbit coupling between the low-lying excited states allows to reduce the excited state lifetimes down to 200 ns for the very deep-blue CMA emitters (420 nm, 100% PLQY). This is five-fold shorter compared to benchmark iridium emitters that enabled the fabrication of the deep-blue CMA OLED with significantly improved device lifetime (LT 50 from several minutes to hours). We will also discuss the molecular design concepts to realize near-UV (down to 390 nm) and near-IR (up to 860 nm) CMA materials and proof-of- concept OLED devices to demonstrate the applied potential of the new CMA materials in this work. References 1. Di, D.; Romanov, A. S.; et al. Science. 2017, 356, 159–163;
2. Conaghan, et al., Adv. Mater. 2018, 30, 1802285; 3. Q. Gu, et al., Chem. Mater., 2022, 34(16), 7526–7542; 4. A.P. M. Reponen et al., Adv. Opt. Mater., 2022, 2200312.
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