Ion Migration in Perovskite Light‐Emitting Diodes: Mechanism, Characterizations, and Material and Device Engineering

Advanced Materials, Год журнала: 2021, Номер 34(19)

Опубликована: Ноя. 30, 2021

In recent years, perovskite light-emitting diodes (PeLEDs) have emerged as a promising new lighting technology with high external quantum efficiency, color purity, and wavelength tunability, well as, low-temperature processability. However, the operational stability of PeLEDs is still insufficient for their commercialization. The generation migration ionic species in metal halide perovskites has been widely acknowledged primary factor causing performance degradation PeLEDs. Herein, this topic systematically discussed by considering fundamental engineering aspects ion-related issues PeLEDs, including material processing origins ion generation, mechanisms driving migration, characterization approaches probing distributions, effects on device stability, strategies management Finally, perspectives remaining challenges future opportunities are highlighted.

Язык: Английский

---

Blue light-emitting diodes based on quasi-two-dimensional perovskite with efficient charge injection and optimized phase distribution via an alkali metal salt

Nature Electronics, Год журнала: 2023, Номер 6(5), С. 360 - 369

Опубликована: Апрель 27, 2023

Язык: Английский

---

Zwitterions Narrow Distribution of Perovskite Quantum Wells for Blue Light‐Emitting Diodes with Efficiency Exceeding 15%

Advanced Materials, Год журнала: 2022, Номер 35(3)

Опубликована: Ноя. 18, 2022

While quasi-two-dimensional (quasi-2D) perovskites have emerged as promising semiconductors for light-emitting diodes (LEDs), the broad-width distribution of quantum wells hinders their efficient energy transfer and electroluminescence performance in blue emission. In particular, underlying mechanism is closely related to crystallization kinetics has yet be understood. Here first time, influence bifunctional zwitterions with different coordination affinity on quasi-2D systematically investigated. The can coordinate Pb2+ also act co-spacer organic species perovskites, which collectively inhibit aggregation colloidal precursors shorten distance wells. Consequently, restricted nucleation high-n phases promoted growth low-n are achieved moderately coordinated zwitterions, leading final film a more concentrated n improved efficiency. It thus enables high-efficiency LEDs recorded external efficiency 15.6% at 490 nm, operation stability been prolonged 55.3 min. These results provide useful directions tuning expected lead high-performance perovskite LEDs.

Язык: Английский

---

Enriched‐Bromine Surface State for Stable Sky‐Blue Spectrum Perovskite QLEDs With an EQE of 14.6%

Advanced Materials, Год журнала: 2022, Номер 34(37)

Опубликована: Июль 30, 2022

Halogen vacancies are of great concern in blue-emitting perovskite quantum-dot light-emitting diodes because they affect their efficiency and spectral shift. Here, an enriched-bromine surface state is realized using a facile strategy that employs PbBr2 stock solution for anion exchange based on Cd-doped quantum dots. It found the doped Cd ions expected to reduce formation energy halogen filled by external bromine ions, excess free enriched anchoring with as sites, accompanied shedding long-chain ligands during process, resulting Br-rich "neat" surface. Moreover, exhibits good passivation defects controlled QDs simultaneously increases exciton binding energy, leading excellent optical properties stability. Finally, sky-blue emitting (QLEDs) (490 nm) conducted record 14.6% current 19.9 cd A-1 . Meanwhile, electroluminescence spectra exhibit stability negligible shifts under constant operating voltage from 3 7 V. This paves way improving QLEDs.

Язык: Английский

---

Passivation strategies for mitigating defect challenges in halide perovskite light-emitting diodes

Joule, Год журнала: 2023, Номер 7(2), С. 272 - 308

Опубликована: Фев. 1, 2023

Язык: Английский

---

A Multifunctional Additive Strategy Enables Efficient Pure‐Blue Perovskite Light‐Emitting Diodes

Advanced Materials, Год журнала: 2023, Номер 35(35)

Опубликована: Май 11, 2023

Lead halide perovskites have shown exceptional performance in light-emitting devices (PeLEDs), particularly producing significant electroluminescence sky-blue to near-infrared wavelengths. However, PeLEDs emitting pure-blue light at 465-475 nm are still not satisfactory. Herein, efficient and stable reported by controlling phase distribution, passivation of defects, as well surface modifications using multifunctional phenylethylammonium trifluoroacetate (PEATFA) reduced-dimensional p-F-PEA2 Csn-1 Pbn (Br0.55 Cl0.45 )3n+1 polycrystalline perovskite films. Compared with 4-fluorophenylethylammonium (p-F-PEA+ ) the pristine films, (PEA+ has lower adsorption energy while interacting perovskites, resulting large-n low-dimensional which can greatly facilitate charge transport within The interaction between CO group (TFA- significantly reduces defects Additionally, electron-giving CF3 TFA- uplifts potential smooth electronic injection devices. additive strategy leads elevated radiative recombination carrier films As a result, exhibit maximum external quantum efficiency (EQE) 11.87% 468 spectral output, highest date for PeLEDs. Thus, this study extends way high-efficiency LED polycrystal

Язык: Английский

---

Focus on perovskite emitters in blue light-emitting diodes

Light Science & Applications, Год журнала: 2023, Номер 12(1)

Опубликована: Июль 24, 2023

Abstract Blue perovskite light-emitting diodes (PeLEDs) are essential in pixels of displays, while their progress lags far behind red and green counterparts. Here, we focus on recent advances blue PeLEDs systematically review the noteworthy strategies, which categorized into compositional engineering, dimensional control, size confinement, optimizing microstructures, energy landscapes, charge behaviors wide-bandgap emitters (bandgap >2.5 eV). Moreover, stability related devices is discussed. In end, propose a technical roadmap for fabrication state-of-the-art to chase achieve comparable performance with other two primary-color devices.

Язык: Английский

---

Methylammonium-free wide-bandgap metal halide perovskites for tandem photovoltaics

Nature Reviews Materials, Год журнала: 2023, Номер 8(12), С. 822 - 838

Опубликована: Ноя. 2, 2023

Язык: Английский

---

Regulating Perovskite Crystallization through Interfacial Engineering Using a Zwitterionic Additive Potassium Sulfamate for Efficient Pure‐Blue Light‐Emitting Diodes

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(7)

Опубликована: Янв. 3, 2024

Quasi-two-dimensional (quasi-2D) perovskites are emerging as efficient emitters in blue perovskite light-emitting diodes (PeLEDs), while the imbalanced crystallization of halide-mixed system limits further improvements device performance. The rapid caused by Cl doping produces massive defects at interface, leading to aggravated non-radiative recombination. Meanwhile, unmanageable is prone facilitate formation nonuniform low-dimensional phases, which results energy loss during exciton transfer process. Here, we propose a multifunctional interface engineering for nucleation and phase regulation incorporating zwitterionic additive potassium sulfamate into hole transport layer. By using ions (K

Язык: Английский

---

High-Performance Blue Perovskite Light-Emitting Diodes Enabled by Synergistic Effect of Additives

Nano Letters, Год журнала: 2024, Номер 24(4), С. 1268 - 1276

Опубликована: Янв. 19, 2024

While quasi-two-dimensional (quasi-2D) perovskites have good properties of cascade energy transfer, high exciton binding energy, and quantum efficiency, which will benefit high-efficiency blue PeLEDs, inefficient domain distribution management unbalanced carrier transport impede device performance improvement. Herein, (2-(9H-carbazol-9-yl)ethyl)phosphonic acid (2PACz) methyl 2-aminopyridine-4-carboxylate (MAC) were simultaneously introduced to a quasi-2D perovskite film. Relying on the synergistic effect 2PACz MAC, it not only modulates phase inhibiting n = 2 but also greatly improves electrical property As result, as-modified PeLED demonstrated an external efficiency (EQE) 17.08% luminance 10142 cd m–2. This study exemplifies among dual additives offers new effective additive strategy modulating building balanced transport, paves way for fabrication highly efficient PeLEDs.

Язык: Английский

---