Emission Wavelength and Efficiency Tuning of Monoatomic Multiresonance Emitters Using a Multiresonance Manager
Jihoon Kang, Sangmo Kim, Soon Ok Jeon, Ha Lim Lee, Inkoo Kim, Unhyeok Jo, Seungwon Han, Joonghyuk Kim, Yongsik Jung, Hye Jin Bae, Jong Soo Kim, Hyeonho Choi, Jun Yeob Lee
Abstract
Abstract A molecular design strategy for managing the emission energy and energy levels while enhancing the emission efficiency of monoatomic multiresonance (MR) emitters based on a fused indolocarbazole (ICz) chromophore is developed by introducing a cyano (CN) unit as an MR manager. The MR manager intensifies the short‐range charge transfer character of the fused ICz‐based blue emitter, resulting in pure‐blue emission with a narrow emission spectrum and an enhanced photoluminescence quantum yield. As a result, the CN MR manager‐modified ICz derivative demonstrates a high external quantum efficiency (EQE) of 23.1%, a small full width at half maximum of 22 nm, and a pure‐blue color coordinate of (0.142, 0.061). In addition, the introduction of the MR manager enables the fabrication of a blue phosphor‐sensitized fluorescence device with an EQE of 24.6% while maintaining the narrow emission spectrum.