High-performance Light-emitting Diodes Research Articles

High-Performance Red Quantum Dot Light-Emitting Diodes via Exciton Harvesting Based on All-Organic Charge Transport Layers

High-Performance Red Quantum Dot Light-Emitting Diodes via Exciton Harvesting Based on All-Organic Charge Transport Layers

Enhanced Hole-Injecting Interface for High-Performance Deep-Blue Perovskite Light-Emitting Diodes Using Dipole-Controlled Self-Assembled Monolayers.

The Blue electroluminescence (EL) with high brightness and spectral stability is imperative for full-color perovskite display technologies meeting the Rec. 2020 standard. However, deep-blue perovskite light-emitting diodes (PeLEDs) lag behind their green- or red-emitting counterparts in brightness, quantum efficiency, and operational stability. Additionally, the Cl-/Br- mixed-halide perovskites with wide bandgap typically designed for deep-blue emitters are prone to degradation quickly under high operating bias due to low energy for halide migrations and vacancies formation, posing a significant challenge to spectral/operative stabilities. To address these issues, high-performance deep-blue PeLEDs are demonstrated by tuning the interface properties with Br-2ETP, a self-assembled monolayer (SAM) molecule engineered for a high dipole moment. The Br-2EPT-based hole-injecting interface facilitates favorable energy level alignment between indium tin oxide and the deep-lying valence band of the perovskite layer, suppressing the hole-injecting barrier and non-radiative charge recombination. Excellent perovskite film morphologies are observed at the top and buried surfaces by Br-2EPT, improving the balance of carrier injection for light emission efficiency. Consequently, the devices exhibit deep-blue electroluminescence at 457nm, with an external quantum efficiency of 6.56% and spectral/operative stabilities.

Exciton Dynamics in Layered Halide Perovskite Light-Emitting Diodes.

Layered halide perovskites have garnered significant interest due to their exceptional optoelectronic properties and great promises in light-emitting applications. Achieving high-performance perovskite light-emitting diodes (PeLEDs) requires a deep understanding of exciton dynamics in these materials. This review begins with a fundamental overview of the structural and photophysical properties of layered halide perovskites, then delves into the importance of dimensionality control and cascade energy transfer in quasi-2D PeLEDs. In the second half of the review, more complex exciton dynamics, such as multiexciton processes and triplet exciton dynamics, from the perspective of LEDs are explored. Through this comprehensive review, an in-depth understanding of the critical aspects of exciton dynamics in layered halide perovskites and their impacts on future research and technological advancements for layered halide PeLEDs is provided.

Enhancing the emissive film quality: A new role of TADF materials for high-performance blue perovskite light-emitting diodes

Thermally activated delayed fluorescence (TADF) materials are widely used in the field of organic light-emitting diodes (OLEDs) because they can capture both singlet and triplet excitons for light emission. However, only scare attention has been paid to the application of TADF materials in perovskite LEDs (PeLEDs) and the understanding of effects of TADF materials in PeLEDs is limited. In this study, a new role of TADF materials for achieving high-quality perovskite films to enhance the performance of PeLEDs is emphasized. TADF materials are introduced into quasi-2D blue PeLEDs to assist in the crystallization of perovskites during film annealing and ensure the formation of high-quality films with reduced defects, enhancing device performance. Additionally, a step-like hole transport layer has been constructed to reduce the hole transport barrier, which can further enhance the performance of PeLEDs. The resultant blue PeLEDs exhibits an external quantum efficiency of 5.44 %, which is 12.7-fold higher than that of the control device. Furthermore, a turn-on voltage of 2.6 V is achieved, which is the lowest for TADF-based blue PeLEDs. The findings may not only unlock a new role of TADF materials in blue PeLEDs, but also provide an alternative pathway to achieve high-performance PeLEDs.

Customized Cyan Phosphors for Efficient Full-Spectrum Illumination and Fingerprint Detection.

Traditional lighting methods have environmental and efficiency drawbacks. These methods are gradually being overshadowed by light-emitting diodes (LEDs) because of their superior color rendering and energy efficiency. In this study, color-tunable NaBa2(Ba/Sr/Ca)Si2O7F:Eu2+ phosphors are successfully designed by modulating the local crystal field environment through homodominant-group cation substitution, thereby allowing for a spectral shift from blue to bright cyan. Detailed structural analysis of the samples demonstrated the synthesis of high-quality solid-solution materials. A comprehensive examination of the phosphor crystal structure, photoluminescence properties, and fluorescence lifetime reveal that the cyan phosphor possesses a remarkable internal quantum efficiency (IQE = 93%) and low thermal quenching characteristics (I423 K/I303 K = 84%). The results illustrate the critical role of Eu2+-activated cyan phosphors in reducing the spectral gap to attain a natural white-light spectrum, which is indispensable for achieving high color fidelity. The practical application of cyan phosphors in the fabrication of high-performance white LED (WLED) (Ra = 96.8) and fingerprint detection is validated, demonstrating their extensive utility in enhancing visual accuracy and identification.

PEDOT:PSS-Free Quantum-Dot Light-Emitting Diode with Enhanced Efficiency and Stability.

Although high-performance quantum-dot light-emitting diodes (QLEDs) have been achieved, their stability is still limited due to the use of unstable PEDOT:PSS as the hole injection layer (HIL). Here, we developed a PEDOT:PSS-free QLED by using a binary PTAA:F4-TCNQ HIL. Because the PTAA, with a highest occupied molecular orbital (HOMO) level of ∼5.20 eV, can facilitate hole injection from ITO to the hole transport layer, and the F4-TCNQ can act as the electron acceptor dopant to improve the hole density and hole mobility of PTAA, the PTAA:F4-TCNQ HIL can exhibit excellent hole injection capability. As a result, the PEDOT:PSS-free QLED can exhibit a high EQE of 24.19% and an impressive brightness of 367,200 cd/m2, which are significantly higher than those of conventional QLEDs. Moreover, due to the improvement of device performance and the removal of PEDOT:PSS, the PEDOT:PSS-free QLED can also exhibit a high T95 operational lifetime of 4206 h at 1000 cd/m2 and an excellent T80 shelf lifetime of 207.41 h at 136400 cd/m2, which are about 1.6- and 3.3-fold those of conventional QLEDs, respectively. We believe that the demonstrated PEDOT:PSS-free QLED, with higher performance and stability, will promote the practical application of QLEDs in displays.

Blue Light-Emitting Diodes Based on Pure Bromide Perovskites.

Blue perovskite light-emitting diodes (LEDs) are essential for the creation of full-color displays and white-light illumination, and some significant progress is made in recent years. However, most high-performance blue perovskite LEDs are currently based on mixed-halide perovskites and suffer from unstable spectra due to inevitable halide phase segregation, which is unfavorable for the application of blue perovskite LEDs. In contrast, blue emissions from pure bromide perovskites generally exhibit stable spectra (consistent emission peak positions and spectral shapes) and are worthy of attention. In this review, the recent advances in blue LEDs based on pure bromide perovskites according to different strategies are classified and summarized. Moreover, the challenges related to poor charge injection, high defect-state density, lack of high-performance in the deeper blue region, and inferior operational stability are addressed. Finally, an outlook is provided on feasible future research directions for highly bright, efficient, and stable blue perovskite LEDs.

Interfacial Modification of ZnO/ZnMgO Bilayer for Efficient and Stable InP Quantum Dot Light-Emitting Diodes via Ultraviolet Ozone Treatment.

The development of efficient charge transport layers is crucial for realizing high-performance and stable quantum dot light-emitting diodes (QD-LEDs). The use of a ZnO/ZnMgO bilayer as an electron transporting layer (ETL) has garnered considerable attention. This configuration leverages the high electron mobility of ZnO and the favorable surface state of ZnMgO. Furthermore, the versatility of this configuration extends to its wide range of thickness tunability, rendering it suitable for the construction of thick devices for top-emitting structures with microcavities. However, despite the promising attributes of this bilayer configuration, the impact of the ZnO/ZnMgO bilayer ETL interface on QD-LEDs performance remains largely unexplored. Thus, this study investigated the effect of ultraviolet ozone (UVO) treatment on the stabilization of the ZnO/ZnMgO interface. UVO treatment was found to significantly enhance luminance uniformity across the QD-LEDs emission area while improving operational stability by over 4-fold. Comprehensive analyses employing X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy confirmed that UVO treatment significantly reduced the defect states of the hydroxyl groups and removed the insulating native ethanolamine ligands, thereby facilitating improved and uniform electron transport. Moreover, the effectiveness of UVO treatment in enhancing electron transport was supported by impedance analyses. Therefore, this paper presents an effective approach for enhancing the interface of a highly potent ZnO/ZnMgO bilayer ETL, which can ultimately improve the luminance uniformity and stability of QD-LEDs.

High-Performance perovskite quantum dots light-emitting diodes with hole transport layer engineering and synergetic outcoupling enhancement

Perovskite quantum dot light-emitting diodes (PeQLEDs) are frequently considered as the most promising alternatives to organic light-emitting diodes (OLEDs). However, the efficiency of PeQLEDs remains inferior to OLEDs due to suboptimal charge carrier transport and intrinsic light outcoupling efficiency (ηout). Herein, a combination of hole transport layer (HTL) engineering and substrate engineering is demonstrated to improve the charge injection and ηout of PeQLEDs. To replace the conventional PEDOT:PSS, a novel HTL bilayer based on modified PEDOT:PSS and PVK with a lower refractive index and fewer trap densities at the HTL-QDs interface is developed. Additionally, this study identifies the ideal thickness of ITO for achieving optimal ηout of PeQLEDs through optical simulations and experimental validation. Based on the synergistic use of HTL bilayer and 70-nm-thick ITO, the PeQLEDs achieved an optimal external quantum efficiency of 17.96 % at a luminance of 1763 cd/m2 and 15.19 % at 8300 cd/m2 without using any external outcoupling structure, indicating a low efficiency roll-off.

High-efficiency RbASiF6:Mn4+ (A = K, Cs) phosphors obtained by one-step green synthesis method

Red-emitting Mn4+-doped fluoride phosphors are recognized as promising materials for high-performance warm white light-emitting diodes (WLEDs). However, the extensive use of toxic hydrofluoric acid in traditional synthesis methods hinders their development and commercialization. Furthermore, the traditional solid-phase method often has cumbersome sintering steps, high temperature, long holding time, and certain safety hazards, so it is very necessary to develop a green synthesis method with simple steps and low energy consumption. In this study, a low-temperature solid-state method is proposed to synthesize RbASiF6:Mn4+ (A = K, Cs) phosphors by one step. Optimal emission intensities were observed at Mn4+ concentrations of 1.2 % in RbKSiF6 and 2.1 % in RbCsSiF6. These phosphors demonstrated high thermal stability. At 423 K, the photoluminescence intensities of RbKSiF6:1.2 %Mn4+ and RbCsSiF6:2.1 %Mn4+ reached 114 % and 87 % of their respective values at room temperature. Meanwhile, the chromaticity shifts were almost negligible, and high color purity was achieved for both phosphors. The electro-optical performance of WLED devices utilizing these phosphors, in combination with YAG:Ce3+ and GaN chips, showed high color rendering indices (CRI) and low correlated color temperatures (CCT) across varying currents. Specifically, under a driving current of 20 mA, the device incorporating RbKSiF6:1.2 %Mn4+ exhibited a CRI of 94 and a CCT of 3732 K, with a luminous efficacy of 61 lm/W. These findings highlight the potential of green-synthesized RASFM phosphors in advancing the application of warm WLEDs.

Efficient and Near-Zero Thermal Quenching Cr3+-Doped Garnet-Type Phosphor for High-Performance Near-Infrared Light-Emitting Diode Applications.

In recent years, near-infrared (NIR) phosphors have attracted great research interest due to their unique physical properties and broad application prospects. However, obtaining NIR phosphors with both high quantum efficiency and excellent thermal stability remains a great challenge. In this study, novel NIR Ca3Mg2ZrGe3O12:Cr3+ phosphors were successfully prepared using a high-temperature solid-phase method, and the structure and luminescent properties of the material were systematically investigated. Ca3Mg2ZrGe3O12:0.01Cr3+ emits NIR light in the range of 600 to 900 nm with a peak at 758 nm and a half-height width of 89 nm under the excitation of 457 nm blue light. NIR luminescence shows considerable quantum efficiency, and the internal quantum efficiency of the optimized sample is up to 68.7%. Remarkably, the Ca3Mg2ZrGe3O12:0.01Cr3+ phosphor exhibits a near-zero thermal quenching behavior, and the luminescence intensity of the sample at 250 °C maintains 92% of its intensity at room temperature. The mechanism of high thermal stability has been elucidated by calculating the Huang Kun factor and activation energy. Finally, NIR pc-LED devices prepared from Ca3Mg2ZrGe3O12:0.01Cr3+ phosphor with commercial blue LED chips have good performance, proving that this Ca3Mg2ZrGe3O12:0.01Cr3+ NIR phosphor has potential applications in night vision and biomedical imaging.

Bifunctional Ligand Passivation Enables Stable Blue Mixed-Halide CsPb(Br/Cl)3 Perovskite Quantum Dots toward Light-Emitting Diodes.

Mixed-halide CsPb(Br/Cl)3 perovskite quantum dots (PeQDs) have attracted extensive attention in light-emitting diodes (LEDs), but their low photoluminescent efficiency and especially poor stability impede their practical applications. Here, we employ bifunctional didodecyldimethylammonium thiocyanide (DDASCN) with a pseudohalogen SCN- and branched DDA+ to obtain blue-emitting CsPbBr2Cl PeQDs. DDASCN significantly boosts the photoluminescence quantum yield to 92% by inhibiting nonradiative recombination. Importantly, DDASCN PeQDs show excellent stabilities against air, UV light, heat, and polar solvents. These improved performances were explained by density functional theory calculation, which shows that SCN- fills the Cl- vacancy by simultaneously binding with undercoordinated Pb2+ and Cs+, while DDA+ connects undercoordinated Br- and lies parallel to the PeQD core, leading to efficient passivation and a strong binding capacity. Finally, we achieved high-performance white LEDs by integrating our PeQDs, resulting in a color-rendering index of 92.9, a color gamut of 119.61%, and chromaticity coordinates of (0.33, 0.33). This provides an effective method to obtain efficient and stable CsPb(Br/Cl)3 PeQDs for practical applications.

Highly efficient AlGaN-based deep-ultraviolet light-emitting diodes: from bandgap engineering to device craft

AlGaN-based light-emitting diodes (LEDs) operating in the deep-ultraviolet (DUV) spectral range (210–280 nm) have demonstrated potential applications in physical sterilization. However, the poor external quantum efficiency (EQE) hinders further advances in the emission performance of AlGaN-based DUV LEDs. Here, we demonstrate the performance of 270-nm AlGaN-based DUV LEDs beyond the state-of-the-art by exploiting the innovative combination of bandgap engineering and device craft. By adopting tailored multiple quantum wells (MQWs), a reflective Al reflector, a low-optical-loss tunneling junction (TJ) and a dielectric SiO2 insertion structure (IS-SiO2), outstanding light output powers (LOPs) of 140.1 mW are achieved in our DUV LEDs at 850 mA. The EQEs of our DUV LEDs are 4.5 times greater than those of their conventional counterparts. This comprehensive approach overcomes the major difficulties commonly faced in the pursuit of high-performance AlGaN-based DUV LEDs, such as strong quantum-confined Stark effect (QCSE), severe optical absorption in the p-electrode/ohmic contact layer and poor transverse magnetic (TM)-polarized light extraction. Furthermore, the on-wafer electroluminescence characterization validated the scalability of our DUV LEDs to larger production scales. Our work is promising for the development of highly efficient AlGaN-based DUV LEDs.

Enhanced Quantum Efficiency of Near-IR Perovskite Light Emitting Diodes Via Dual Interfacial Modification

Near-infrared (NIR) light-emitting diodes play a crucial role in a wide range of applications, including sensors, night vision displays, security systems, medicine, spectroscopy, and military applications. The potential for high-performance NIR perovskite light-emitting diodes (NIR-PeLEDs) has been highlighted with the impressive advancement of fluorescent perovskite thin films. These PeLEDs exhibit promising features such as a tunable band gap, high color purity, and low non-radiative recombination rates. Despite these advantages, the current state-of-the-art NIR-PeLEDs faces challenges primarily related to poor film quality and increased defect states, leading to limitations in external quantum efficiency (EQE) and operational stability. In addressing these issues, we present a novel dual interfacial modification approach involving the incorporation of fluorinated phenethylammonium iodide (F-PEAI), a bulky organic cation, at both the bottom and top interfaces of perovskite emitting films. The modified interfaces result in perovskite films with a smoother surface morphology, complete coverage, and high crystallinity, leading to a red-shifted fluorescence band extending toward 800 nm. Furthermore, the introduction of F-PEAI facilitates the formation of compact and fine grains in perovskite films, contributing to an enhanced photoluminescence quantum yield (PLQY). Consequently, NIR-PeLEDs modified with F-PEAI demonstrate improved EQE values coupled with enhanced operational stability. The combination of electrical, optical, and physical analyses of both films and devices underscores the effectiveness of the dual interface modification in developing efficient NIR perovskite LEDs suitable for practical applications.

Carbon Quantum Dots with Highly Efficient Bandgap Emission for Electroluminescent Light-Emitting Diodes

Carbon quantum dots (CQDs) feature bright and tunable photoluminescence, solution processability, and low toxicity, showing great potential in optoelectronics. The multicolor fluorescent CQDs were first fabricated as active layers in our lab, and then the high-performance electroluminescent warm white light-emitting diodes (LEDs) were obtained with the synthesized bright red CQDs. More significantly, through designing the triangular structure of the carbon core, fluorescent CQDs first achieved the narrow-bandwidth (∼30 nm) electroluminescent LEDs with appreciable stability, high color purity, and high luminescence performance. These results lay the foundation for the development of next-generation high performance displays based on CQDs. Here, we will report the large-scale synthesis of CQDs with near-unity photoluminescence quantum yield and the synthesis of red (625 nm) phosphorescent carbon quantum dot organic frameworks (CDOFs) with a quantum yield of up to 42.3% and realization of high-efficiency red phosphorescent electroluminescent LEDs. The LEDs based on the CDOFs exhibited a red emission with a maximum luminance of 1818 cd m−2 and an EQE of 5.6%. This work explores the possibility of a new perspective for developing high-performance CQD-based electroluminescent LEDs.References Yuxin Shi, Louzhen Fan, et al., Red Phosphorescent Carbon Quantum Dot Organic Framework-Based Electroluminescent Light-Emitting Diodes Exceeding 5% External Quantum Efficiency, Am. Chem. Soc. 2021, 143, 45, 18941–18951Ting Yuan, Louzhen Fan, et al., Carbon Quantum Dots with Near-Unity Quantum Yield Bandgap Emission for Electroluminescent Light-Emitting Diodes, Angew. Chem. Int. Ed. 2023, e202218568.Fanglong Yuan，Louzhen Fan, et al., Engineering triangular carbon quantum dots with unprecedented narrow bandwidth emission for multicolored LEDs, Nat. Commun., 2018, 9, 2249. Figure 1

Optimization and luminescence studies of Sm3+ doped LiCaBO3 phosphors for high-performance white light-emitting diodes

An undoped and a series of orange-red emitting LiCaBO3:Sm3+ (x = 0.5–3 mol%) phosphors have been synthesized using a highly reliable and cost-effective combustion method. The synthesized phosphors were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), photoluminescence spectroscopy (PL), and Diffuse Reflectance spectroscopy (DRS). The structural studies of the LiCaBO3:Sm3+phosphor confirm the single-phase orthorhombic structure with space group Pbca and the presence of borate anionic groups. Upon near-UV excitation at 405 nm, the PL emission spectra show four emission peaks centered at 564 nm, 602 nm, 650 nm, and 708 nm corresponding to the 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 transitions respectively resulting in the emission of orange-red light. The optimum dopant concentration of Sm3+ion was 1 mol% and the main mechanism of concentration quenching was calculated using Dexter's theory. The bandgap of the undoped phosphor was found to be 5.31 eV. The CIE chromaticity coordinates are (0.56, 0.40) which confirms the orange-red emission. The obtained results indicate that the synthesized phosphor can be a potential candidate for application in solid-state lighting devices.

High-performance sky-blue quasi-2D perovskite light-emitting diodes via synergistic defect passivation and phase narrowing strategies

Quasi-2D perovskite light-emitting diodes (PeLEDs) are considered as one of the most promising candidates for next-generation displays. Yet, the unstable electroluminescent spectra and inferior performance of blue PeLEDs hinder their commercial use. Herein, we demonstrate highly efficient quasi-2D pure bromide (QPB) sky-blue PeLEDs based on an oxygen-rich triethyl 2-acetylcitrate (TEAC) additive. The TEAC additive contains four C = O functional groups, offering several coordination sites to simultaneously passivate multiple bromine vacancy defects. Furthermore, it inhibits the growth of large n (n ≥ 5) phases to achieve narrow phases distribution. As a result, the TEAC-modified PeLEDs show sky-blue emission at 494 nm, with maximum current efficiency and external quantum efficiency up to 29.1 cd/A and 18.5 %, respectively. Moreover, the T50 lifetime of TEAC-modified PeLED is about 25 times higher than that of pristine PeLEDs. Our results provide a reliable approach to realizing high-efficiency blue quasi-2D PeLEDs.

Enhancing the performance of InGaN-based near-infrared light-emitting diodes under a weakly polarized electric field

This work presents a simulation analysis of nitride multi-quantum-well near-infrared light-emitting diodes (LEDs) with an emission wavelength of 1300 nm using Crosslight-APSYS software. The polarization electric field at the quantum wells was effectively tuned by adopting an Al0.02Ga0.19In0.79N quaternaries compound as the barrier for the In0.78GaN quantum wells, resulting in a near-zero polarization electric field. This approach significantly reduced band bending and increased the overlap of electron-hole wave functions within the quantum wells. Consequently, the internal quantum efficiency (IQE) in the nitride near-infrared LED improved, and the droop effect was significantly reduced. The Auger recombination mechanism that influences the droop effect was further analyzed. This provides an efficient approach for the development of high-performance InGaN-based near-infrared light-emitting diodes with high indium content.

High Stability and Corrosion-Resistant Gas of Recyclable and Versatile Manganese-Doped Lead-Free Double Perovskite Crystals toward Novel Functional Fabric and Photoelectric Device.

Lead-free halide perovskites possess excellent photoelectric properties, making them widely used in the photoelectric fields. Herein, lead-free double perovskite crystals (PCs) doped with manganese (Cs2NaInCl6:Mn2+) are successfully prepared by the more energy-efficient crystallization method. The crystals emit bright orange-red light under the ultraviolet (UV) lamp, showing unique optical properties. They have the highest photoluminescence quantum yield of 42.91%. The white light-emitting diodes (LEDs) are fabricated using these perovskite crystals, which show a color rendering index of 92 and external quantum efficiency (EQE) as high as 16.3%. Furtherly, perovskite-modified fiber paper made of aramid chopped fibers (ACFs) and polyphenylene sulfide (PPS) exhibited fluorescent properties under different conditions. This paper combines fiber composite technology with PPS fiber filter bags, which are widely used in environmental protection, for the first time and demonstrates functional fiber filter bags with fluorescent characteristics. This filter bag provides an idea for the automatic detection of industrial filtration. Meanwhile, after being exposed to industrial waste gas for 60h, the filter bag can maintain superior fluorescence performance. In this study, lead-free double perovskites are synthesized using an efficient method for preparing high-performance LEDs and high-stability fluorescent fibers. Concurrently, the application of perovskites in environmental protection is expanded.

Drag force shear manipulating ligand distribution at perovskite buried interface enables efficiently suppressed EQE roll-off of perovskite light-emitting diodes

Effectively manipulating the ligand distribution at the perovskite buried interface is critical for achieving high-performance nanocrystal-based perovskite light-emitting diodes (PeLEDs). However, it is challenging to realize it due to the non-exposed feature of the buried interface. Here, the drag force shear (DFS) is utilized to successfully regulate the ligand distribution at the perovskite buried interface which can effectively suppress the EQE roll-off of devices. By manipulating the ligand distribution at the perovskite buried interface, it is revealed that a more ligand preservation could result in an improved defect passivation leading to higher EQE, while the carrier injection barrier is increased simultaneously making devices suffer from severe EQE roll-off and decreased luminance, and vice versa. With the help of optimizing the ligand distribution by manipulating the DFS, the balance between carrier injection and interfacial defect passivation is successfully achieved. Resultantly, an enhanced EQE of 17.24 % with substantially suppressed EQE roll-off is reached, culminating in a remarkable luminance of 61,900 cd/m2. This work presents an efficient approach to control ligand distribution at the perovskite buried interface and offers valuable insights for realizing high luminance and low EQE roll-off of PeLEDs.