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Updated: May 15, 2026

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
Tailored Synergistic Vibronic Progression and Charge Transfer in 1,2-BN-Heteroarenes for Efficient and Stable
Han Zhang1, Chenfa Xiao2, Baoxi Li2
1Department of Chemistry, and the Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Kowloon, Hong Kong 999077, P. R. China.
Abstract:
The development of organic narrowband emitters faces long-standing challenges in expanding structural diversity, improving synthetic efficiency, elucidating narrowband emission mechanisms, and enhancing overall electroluminescence (EL) performance. Herein, we report a new class of narrowband emitters based on 1,2-BN-heteroarenes, enabled by a systematic design strategy that integrates planar locking, peripheral rotation, and BN-unit extension to tailor vibronic progression in alignment with the principles governing narrowband emission. They are readily synthesized using a borenium species-promoted, amine-directed one-pot borylation in yields over 80%, and exhibit tunable emission colors arising from interplay among locally excited (LE), long-range charge-transfer (CT), and short-range CT states. Representative emitters [B-N]2 and [B-N]2-DPA exhibit peak emissions at 460 and 482 nm with ultranarrow full widths at half-maximums (FWHMs) of 16 and 18 nm, respectively, and near-unity photoluminescence (PL) quantum yields. Furthermore, by employing a "hot-exciton layer" design to facilitate exciton dynamics, the corresponding narrowband organic light-emitting diodes (OLEDs) deliver a high maximum external quantum efficiency (EQE) of 29.6%, an exceptionally low efficiency roll-off of 5.7% at 1000 cd m-2, and superior operational stability compared with the control 1,4-BN-heteroarene. These findings offer new insights into the design of narrowband emitters with diverse structures and high EL performance.
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