Zuo-Quan Jiang

Heteroatom‐fused ring systems featuring topological architectures represent a powerful platform for engineering molecular properties. Herein, we report two topology‐engineered heteroaromatic emitters, BO‐DPAB3 and BO‐DPAB4. Through precise modulation of the number, ratio, and spatial arrangement of B, N, and O heteroatoms, a twisted π‐conjugated framework with finely tuned electronic structure was constructed. The controllable multi‐boron π‐extension enables multidirectional electron delocalization while preserving localized excited‐state characteristics. The rigid twisted topology minimizes structural relaxation and weakens intermolecular interactions, thereby reducing aggregation‐caused quenching and enabling narrowband deep‐blue emission at 453 and 449 nm with a full‐width at half‐maximum (FWHM) of 24 and 20 nm, respectively. Notably, organic light‐emitting diode (OLED) devices based on the symmetric tetraboron emitter BO‐DPAB4 achieve a maximum external quantum efficiency (EQE _max ) of 30.1% and a Commission Internationale de l’Éclairage (CIE) coordinate of (0.138, 0.073). This work establishes twisted multi‐boron topological π‐extension as an effective molecular design paradigm for developing deep‐blue emitters with high efficiency and color purity.

Heteroatom‐fused ring systems featuring topological architectures represent a powerful platform for engineering molecular properties. Herein, we report two topology‐engineered heteroaromatic emitters, BO‐DPAB3 and BO‐DPAB4. Through precise modulation of the number, ratio, and spatial arrangement of B, N, and O heteroatoms, a twisted π‐conjugated framework with finely tuned electronic structure was constructed. The controllable multi‐boron π‐extension enables multidirectional electron delocalization while preserving localized excited‐state characteristics. The rigid twisted topology minimizes structural relaxation and weakens intermolecular interactions, thereby reducing aggregation‐caused quenching and enabling narrowband deep‐blue emission at 453 and 449 nm with a full‐width at half‐maximum (FWHM) of 24 and 20 nm, respectively. Notably, organic light‐emitting diode (OLED) devices based on the symmetric tetraboron emitter BO‐DPAB4 achieve a maximum external quantum efficiency (EQE _max ) of 30.1% and a Commission Internationale de l’Éclairage (CIE) coordinate of (0.138, 0.073). This work establishes twisted multi‐boron topological π‐extension as an effective molecular design paradigm for developing deep‐blue emitters with high efficiency and color purity.

Blue organic light‐emitting diodes (OLEDs) incorporating multiple‐resonance (MR) emitters have achieved exceptional color purity and external quantum efficiencies (EQEs), yet their operational stability remains limited by triplet accumulation on terminal emitters (TEs). In this study, we report a space‐confined triplet‐scavenging strategy that spatially couples an anthracene‐based triplet‐scavenging unit to the MR core while electronically decoupling them. This architecture enables efficient triplet dissipation without disturbing the intrinsic singlet emission of the MR‐core. Therefore, the proposed BCzBN‐SF1An preserves narrowband blue emission and high photoluminescence quantum yield, while exhibiting an enlarged singlet‐triplet splitting and suppressed delayed emission, consistent with triplet scavenging effect. In hyperfluorescent (HF) OLEDs, BCzBN‐SF1An exhibits a maximum EQE of 22.2% with a significantly reduced efficiency roll‐off. Notably, the device lifetime is extended to 127 h at LT ₈₀ , a threefold improvement over the parent BCzBN‐based device, without sacrificing color purity or efficiency. Transient electroluminescent measurements further reveal suppressed charge trapping and the elimination of delayed emission from TEs, highlighting the synergistic roles of triplet scavenging and optimized charge carrier dynamics. This work demonstrates comprehensive insights into carrier/exciton dynamics, along with an effective molecular design paradigm for simultaneously achieving high efficiency and long operational lifetime in blue HF‐OLEDs through precise triplet exciton management.

Blue organic light‐emitting diodes (OLEDs) incorporating multiple‐resonance (MR) emitters have achieved exceptional color purity and external quantum efficiencies (EQEs), yet their operational stability remains limited by triplet accumulation on terminal emitters (TEs). In this study, we report a space‐confined triplet‐scavenging strategy that spatially couples an anthracene‐based triplet‐scavenging unit to the MR core while electronically decoupling them. This architecture enables efficient triplet dissipation without disturbing the intrinsic singlet emission of the MR‐core. Therefore, the proposed BCzBN‐SF1An preserves narrowband blue emission and high photoluminescence quantum yield, while exhibiting an enlarged singlet‐triplet splitting and suppressed delayed emission, consistent with triplet scavenging effect. In hyperfluorescent (HF) OLEDs, BCzBN‐SF1An exhibits a maximum EQE of 22.2% with a significantly reduced efficiency roll‐off. Notably, the device lifetime is extended to 127 h at LT ₈₀ , a threefold improvement over the parent BCzBN‐based device, without sacrificing color purity or efficiency. Transient electroluminescent measurements further reveal suppressed charge trapping and the elimination of delayed emission from TEs, highlighting the synergistic roles of triplet scavenging and optimized charge carrier dynamics. This work demonstrates comprehensive insights into carrier/exciton dynamics, along with an effective molecular design paradigm for simultaneously achieving high efficiency and long operational lifetime in blue HF‐OLEDs through precise triplet exciton management.

Correction for ‘Theoretical insights into site-specific heavy-atom effects on MR-TADF emitters: modulation of spin–orbit coupling and color purity’ by Shi-Jie Ge et al. , Chem. Sci. , 2026, https://doi.org/10.1039/d6sc00582a.

In multi-resonance thermally activated delayed fluorescence (MR-TADF) materials, the introduction site of heavy atoms exhibits an antagonistic effect on color purity and spin–orbit coupling.

Near infrared (NIR) light-emitting devices hold significant promise for applications in night vision, telecommunications, and biomedical imaging. Hybrid tandem light-emitting diodes (LEDs) that combine quantum-dot (QD)-based and organic emissive subunits represent a compelling strategy to surpass an external quantum efficiency (EQE) of 30%. However, in series-connected architectures, the intrinsic mismatch in charge-transport properties and distinct efficiency roll-off characteristics between the two emissive units hinder ideal efficiency summation and limit overall device performance under identical current injection. Here, we report a high-performance hybrid NIR tandem LED in which this imbalance is mitigated by selectively enhancing carrier injection and transport in the performance-limiting QD-based emissive unit. Through molecular engineering of the electron-transporting layer and rational design of the charge-generation interface, the electrical characteristics of the QD unit is precisely tailored to match that of the high-efficiency organic NIR emitter. As a result, the hybrid tandem device achieves a near-ideal voltage addition and markedly improved electroluminescence, delivering a peak external quantum efficiency of 35% with stable emission at 780 nm. This work establishes a general design principle for overcoming current-driving imbalance in heterogeneous tandem architectures and paves the way toward high-performance NIR light sources.

A ladder-type π-conjugated framework with multi-heteroatom modulation was designed, enabling 4F-BOB4 to serve as an ultra-narrowband violet-blue multi-resonance emitter with a full width at half maximum of 14 nm and a low CIE _y of 0.03 in OLED device.

Controlling molecular conductance beyond highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO–LUMO) interference is essential for advancing single‐molecule electronics. Here we employ π–σ–π frameworks—linear diphenylmethane and orthogonal 9,9′‐spirobifluorene—to investigate destructive quantum interference (DQI) governed by orbitals on the same side. Four model molecules ( DM22‐MT , DM44‐MT , SF33‐MT , SF44‐MT ) were designed with site‐specific –SMe anchoring groups and examined by scanning tunneling microscope–break junction (STM–BJ) measurements and theoretical simulations. All exhibit intrinsically low conductance, consistent with destructive quantum interference (DQI) effect. Importantly, site‐dependent effects in spiro systems disrupt spiro‐conjugation and alter anchor–electrode coupling, leading to counterintuitive conductance trends. This study provides the first experimental evidence for bilateral DQI in π–σ–π systems and establishes a molecular design strategy for insulating and functionalized single‐molecule devices.

Controlling molecular conductance beyond highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO–LUMO) interference is essential for advancing single‐molecule electronics. Here we employ π–σ–π frameworks—linear diphenylmethane and orthogonal 9,9′‐spirobifluorene—to investigate destructive quantum interference (DQI) governed by orbitals on the same side. Four model molecules ( DM22‐MT , DM44‐MT , SF33‐MT , SF44‐MT ) were designed with site‐specific –SMe anchoring groups and examined by scanning tunneling microscope–break junction (STM–BJ) measurements and theoretical simulations. All exhibit intrinsically low conductance, consistent with destructive quantum interference (DQI) effect. Importantly, site‐dependent effects in spiro systems disrupt spiro‐conjugation and alter anchor–electrode coupling, leading to counterintuitive conductance trends. This study provides the first experimental evidence for bilateral DQI in π–σ–π systems and establishes a molecular design strategy for insulating and functionalized single‐molecule devices.