Judicious Use of Chalcogens in Multiresonant Thermally Activated Delayed Fluorescent Emitters Leads to OLEDs with Efficiencies Exceeding 36% and Showing Mild Efficiency Roll-Off.

ABSTRACT: Strategies that produce OLEDs that simultaneously achieve outstanding electroluminescence efficiency, small efficiency roll-off, good stability, and high color purity remain in strong demand. Herein, we report how judicious decoration of a benzochalcogenophene onto the BCzBN core leads to an acceleration of reverse intersystem crossing (k_RISC) without sacrificing either color fidelity and photoluminescence quantum yield (Φ_PL). Compared with BCzBN, the k_RISC of BN-S and BN-Se are accelerated to 2.5 × 10⁵ and 7.2 × 10⁵ s^-1 from 1.4 × 10⁴ s^-1, each with near-unity Φ_PLs. BN-S and BN-Se show narrowband emission at 483 nm (FWHM of 22 nm) and 485 nm (FWHM of 22 nm). The corresponding non-sensitized

SUBMITTER: Liu F 

PROVIDER: S-EPMC12455388 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature