Jiangshan Chen

Metal halide perovskite light‐emitting diodes (PeLEDs) show immense potential in next‐generation display technologies due to their exceptional optoelectronic properties. However, their operational stability and luminescence brightness remain core bottlenecks restricting their commercialization. To address this issue, this study reports an interference crystallization strategy that regulates crystal facet growth to reshape facet competition. By incorporating L‐theanine (LT) into the precursor solution of FAPbBr ₃ , the functional groups in LT selectively adsorb onto the (100) crystal facets of the perovskite, thereby suppressing the rapid growth of these facets and significantly enhancing the ordering of the crystal arrangement and crystal quality. Subsequently, 2,4,6‐Tris[3‐(diphenylphosphinyl)phenyl]‐1,3,5‐triazine (POT2T) is further introduced to modify the perovskite interface, synergistically passivating interface defects and confining the carrier recombination zone, thereby effectively suppressing interfacial non‐radiative recombination. Consequently, the fabricated green PeLEDs achieve an external quantum efficiency (EQE) of 23.06% and an ultrahigh luminance of 358 135 cd m ⁻² , delivering an outstanding T ₅₀ operational lifetime of 14 923 h at an initial luminance of 100 cd m ⁻² . Furthermore, the optimized device with an active area of 6 mm ² exhibits a response time of 1.01 µs. Thus, this strategy provides new insights for high‐luminance, long‐lifetime and fast‐response PeLEDs, broadening their potential applications.

Pre-synthesized powder and VB ₁ engineering synergistically regulate crystallization and defects, enabling efficient lead-free pure-2D PEA ₂ SnI ₄ PeLEDs.

The emerging micro‐displays and visible light communication demand light‐emitting devices capable of simultaneously achieving high efficiency and ultrahigh brightness under high current injection. Lead‐halide perovskite light‐emitting diodes (PeLEDs) are intrinsically capable of sustaining high efficiency and high brightness, making them highly attractive for micro‐display and visible light communication technologies. While such performance has been well demonstrated in green PeLEDs, blue PeLEDs still lag far behind due to severe nonradiative recombination at high current densities. Herein, we report a potassium thiocyanate (KSCN) interfacial dipole layer strategy for blue PeLEDs that simultaneously improves interfacial energy‐level alignment, suppresses leakage current by forming a compact bottom interface, and regulates the crystallization of perovskite films. Benefiting from the synergistic optimization of interfacial electronic structure and film quality, the resulting devices achieve a maximum external quantum efficiency (EQE) of 17.73% with a narrow emission at 491 nm (FWHM ≈ 15 nm). Meanwhile, the device delivers an ultrahigh luminance of 41890 cd m ⁻² and improved operational stability with a fivefold increase in lifetime. This work demonstrates that interfacial coordination engineering provides an effective route to simultaneously achieve high efficiency and high brightness in blue PeLEDs.

Eco-friendly tin (Sn)-based perovskites are highly promising for near-infrared light-emitting diodes (PeLEDs), but their electroluminescence performance currently lags behind that of their lead-based counterparts due to unsatisfactory crystallization and severe Sn2+ oxidation. Herein, we demonstrate a progressive optimization strategy to enhance the Sn-based perovskite crystallization by employing a self-assembled monolayer (SAM) of 2PACz:PFNBr as the buried interface and subsequently incorporating isophthalic dihydrazide (IPDH) as a bulk additive. The 2PACz:PFNBr SAM effectively retards rapid crystallization and facilitates controlled nucleation, ensuring high crystal quality of Sn-based perovskite films. Furthermore, the multifunctional IPDH additive improves crystallization uniformity and inhibits Sn2+ oxidation, resulting in homogeneous perovskite films with minimized defect density. Ultimately, the champion device demonstrates a record external quantum efficiency (EQE) of 20.15%, a maximum radiance of 125 W sr–1 m–2, and a stable emission peak at 890 nm, setting a new benchmark for Sn-based near-infrared PeLEDs.

One of the primary bottlenecks hindering the widespread adoption of AI-driven exploration of novel materials in the field of organic light-emitting diodes (OLEDs) is the labor-intensive process of constructing high-quality data sets required for training accurate property prediction models. Consequently, the limited availability of complete experimental data impedes a deeper understanding of the underlying materials’ mechanisms. In this work, we introduce a multiagent artificial intelligence framework that autonomously extracts information from PDF-formatted literature, enabling accurate retrieval of molecular structures, properties, detailed measurement conditions, and OLED device architectures. This is achieved by decoupling the complex task of data extraction from PDFs and integrating easily accessible, multiple specialized AI agents. Using this framework, we curated and publicly released data from over 1600 open-access publications, covering most known thermally activated delayed fluorescence (TADF) materials. When applied to this real-world data set, the trained machine learning (ML) models in our framework demonstrated high accuracy in predicting six key properties essential for materials screening. We further investigated the influence of additional experimental conditions on the predictive performance of the machine learning models. Our results demonstrate that lowering the barrier to acquiring OLED-related data using our framework can significantly enhance the prediction accuracy of ML models for emitter screening, accelerating AI-driven material discovery in this field.

In recent years, wide bandgap (WBG) perovskite solar cells (PSCs) have garnered significant attention due to their high open‐circuit voltage ( V _OC ) and superior stability. This review comprehensively examines the bromide‐based (Br‐based) perovskites with bandgaps over 2.0 eV and their applications in photovoltaic devices, discussing research progress and interfacial engineering strategies across several types of WBG perovskites, including cesium lead bromide (CsPbBr ₃ ), CsPbIBr ₂ , methylamine lead bromide (MAPbBr ₃ ), and formamidinium lead bromide (FAPbBr ₃ ). The key challenges in developing Br‐based WBG PSCs include energy level misalignment, high defect density of perovskite films, and residual stress occurring in the fabrication process. Through interfacial passivation, charge transport layer (CTL) optimization, and antisolvent engineering, researchers can modulate perovskite crystallization, mitigate defects, minimize energy level misalignment, enhance carrier transport, release residual stress, and prevent ambient air infiltration, thereby improving the photovoltaic performance and stability of PSCs. Finally, this review prospects for the potential application directions and optimization strategies for Br‐based PSCs.

DMPO passivation and PAM interlayer enable bright, efficient, and stable quasi-2D blue PeLEDs (486 nm) with a 12.94% EQE.

FAPbBr ₃ PeNCs synthesized via LARP showed superior thermal stability. CF ₃ -PEA passivation reduced thermal quenching, retaining 75% PL at 380 K. PMMA encapsulation further improved stability. The champion EL device achieved a maximum EQE of 20.4%.

Quasi‐2D perovskites have demonstrated significant potential for applications in perovskite light‐emitting diodes (PeLEDs). However, issues such as nonradiative recombination induced by defects, energy transfer losses caused by disordered phase distribution, and carrier transport limitation imposed by grain boundary barriers severely hinder the realization of high‐performance PeLEDs. Here, a dual‐additive synergistic strategy is reported that successfully passivates surface defects, shortens intergranular distance, and optimizes phase homogenization of perovskite nanograins in the formamidinium (FA)‐based quasi‐2D perovskite films. The additives of diphenyl(2,4,6‐trimethylbenzoyl)phosphine oxide (DTBPPO) and tris(4‐fluorophenyl)phosphine oxide (TFPPO) are introduced into the precursor solution and anti‐solvent, respectively. DTBPPO is found to anchor adjacent nanograins via C = O and P = O bidentate coordination to reduce the spacing between nanograins and enhance carrier transport. TFPPO is demonstrated to slow down the crystallization rate through hydrogen bonding between fluorine atoms and organic cations, suppressing low‐n phases and promoting energy transfer. Both DTBPPO and TFPPO passivate the surface defects of perovskite nanograins, effectively reducing non‐radiative recombination losses. Ultimately, the dual‐additive synergistic effects yield pure green PeLEDs for Rec. 2020 compliance, with maximum external quantum efficiency of 24.41% and prolonged operational lifetime. The collaborative paradigm of “nanograin bridging‐phase homogenization‐defect passivation” provides new insights for developing high‐performance perovskite optoelectronic devices.

Metal halide perovskites have garnered significant attention in the application of light‐emitting diodes (LEDs) due to their excellent optoelectronic properties. However, the traditional solution preparation of perovskite emissive layers (EMLs) is performed in inert atmosphere, which is not economical for mass production. Herein, a calcium ion (Ca ²⁺ ) confinement (CIC) strategy is proposed to fabricate high‐quality perovskite films with in situ formed supercrystal in air atmosphere. It is found that the incorporation of substantial Ca ²⁺ into perovskite precursors induces self‐aggregates of perovskite nanoparticles with strong exciton localization effect and reduce density of trap states, prolonging the photoluminescence lifetime of the air‐fabrication perovskite films from nanoseconds to microseconds. Based on this CIC strategy, the air‐fabrication supercrystal EMLs present a large enhancement of photoluminescence quantum yields, and the resultant perovskite LEDs (PeLEDs) achieve significantly improved performance with a maximum luminance of approaching 100,000 cd m ⁻² , setting the record luminance for the air‐fabrication PeLEDs. Moreover, the massive Ca ²⁺ reduces the toxicity of the perovskite EMLs and increases the operation lifetime of the air‐fabrication PeLEDs. This work not only addresses the film‐forming challenges of perovskite supercrystal films but also provides a cost‐effective and low‐toxicity solution‐fabrication strategy for fabricating high‐performance PeLEDs in air atmosphere.