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Metal‐halide perovskites (MHPs) are well suited to be vivid natural color emitters due to their superior optical and electrical properties, such as narrow emission linewidths, easily and widely tunable emission wavelengths, low material cost, and high charge carrier mobility. Since the first development of MHP light‐emitting diodes (PeLEDs) in 2014, many researchers have tried to understand the properties of MHP emitters and the limitations to luminescence efficiency (LE) of PeLEDs, and have devoted efforts to increase the LE of MHP emitters and PeLEDs. Within three and half years, PeLEDs have shown rapidly increased LE from external quantum efficiency ≈0.1% to ≈14.36%. Herein, the factors that limit the LE of PeLEDs are reviewed; the factors are characterized into the following groups: i) photophysical properties of MHP crystals, ii) morphological factors of MHP layers, and iii) problems caused by device architectures. Then, the strategies to overcome those luminescence‐limiting factors in MHP emitters and PeLEDs are critically evaluated. Finally, research directions to further increase the LE of MHP emitters and the potential of MHPs as a core component in next‐generation displays and solid‐state lightings are suggested. 相似文献
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Morphology Engineering for High‐Performance and Multicolored Perovskite Light‐Emitting Diodes with Simple Device Structures 下载免费PDF全文
Zhibin Wang Tai Cheng Fuzhi Wang Songyuan Dai Zhan'ao Tan 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(32):4412-4420
The film morphology is extremely significant for solution processed perovskite devices. Through fine morphology engineering without using any additives or further posttreatments, a full‐coverage and high quantum yield perovskite film has been achieved based on one‐step spin‐coating method. The morphologies and film characteristics of MAPbBr3 with different MABr:PbBr2 starting material ratios are in‐depth investigated by scanning electron microscopy, atomic force microscopy, X‐ray diffraction, photoluminescence, and time resolved photoluminescence. High performance organometal halide perovskite light‐emitting didoes (PeLEDs) based on simple device structure of indium tin oxide/poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS)/perovskite/TPBi/Ca/Al are demonstrated. The green PeLED based on MAPbBr3 shows a maximum luminance of 8794 cd m?2 (at 7.3 V) and maximum current efficiency of 5.1 cd A?1 (at 5.1 V). Furthermore, a class of hybrid PeLEDs by adjusting the halide ratios of methylammonium lead halide (MAPbX3, where X is Cl, Br, or I) are also demonstrated at room temperature. These mix‐halogenated PeLEDs show bright luminance (above 100 cd m?2) with narrow and clean emission bands over the wide color gamut. 相似文献
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Enhanced Performance in Fluorene‐Free Organometal Halide Perovskite Light‐Emitting Diodes using Tunable,Low Electron Affinity Oxide Electron Injectors 下载免费PDF全文
Robert L. Z. Hoye Matthew R. Chua Kevin P. Musselman Guangru Li May‐Ling Lai Zhi‐Kuang Tan Neil C. Greenham Judith L. MacManus‐Driscoll Richard H. Friend Dan Credgington 《Advanced materials (Deerfield Beach, Fla.)》2015,27(8):1414-1419
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Sjoerd A. Veldhuis Pablo P. Boix Natalia Yantara Mingjie Li Tze Chien Sum Nripan Mathews Subodh G. Mhaisalkar 《Advanced materials (Deerfield Beach, Fla.)》2016,28(32):6804-6834
Organic–inorganic hybrid perovskites have cemented their position as an exceptional class of optoelectronic materials thanks to record photovoltaic efficiencies of 22.1%, as well as promising demonstrations of light‐emitting diodes, lasers, and light‐emitting transistors. Perovskite materials with photoluminescence quantum yields close to 100% and perovskite light‐emitting diodes with external quantum efficiencies of 8% and current efficiencies of 43 cd A?1 have been achieved. Although perovskite light‐emitting devices are yet to become industrially relevant, in merely two years these devices have achieved the brightness and efficiencies that organic light‐emitting diodes accomplished in two decades. Further advances will rely decisively on the multitude of compositional, structural variants that enable the formation of lower‐dimensionality layered and three‐dimensional perovskites, nanostructures, charge‐transport materials, and device processing with architectural innovations. Here, the rapid advancements in perovskite light‐emitting devices and lasers are reviewed. The key challenges in materials development, device fabrication, operational stability are addressed, and an outlook is presented that will address market viability of perovskite light‐emitting devices. 相似文献
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Yu Tian Chenkun Zhou Michael Worku Xi Wang Yichuan Ling Hanwei Gao Yan Zhou Yu Miao Jingjiao Guan Biwu Ma 《Advanced materials (Deerfield Beach, Fla.)》2018,30(20)
Perovskite light‐emitting diodes (LEDs) have recently attracted great research interest for their narrow emissions and solution processability. Remarkable progress has been achieved in green perovskite LEDs in recent years, but not blue or red ones. Here, highly efficient and spectrally stable red perovskite LEDs with quasi‐2D perovskite/poly(ethylene oxide) (PEO) composite thin films as the light‐emitting layer are reported. By controlling the molar ratios of organic salt (benzylammonium iodide) to inorganic salts (cesium iodide and lead iodide), luminescent quasi‐2D perovskite thin films are obtained with tunable emission colors from red to deep red. The perovskite/polymer composite approach enables quasi‐2D perovskite/PEO composite thin films to possess much higher photoluminescence quantum efficiencies and smoothness than their neat quasi‐2D perovskite counterparts. Electrically driven LEDs with emissions peaked at 638, 664, 680, and 690 nm have been fabricated to exhibit high brightness and external quantum efficiencies (EQEs). For instance, the perovskite LED with an emission peaked at 680 nm exhibits a brightness of 1392 cd m?2 and an EQE of 6.23%. Moreover, exceptional electroluminescence spectral stability under continuous device operation has been achieved for these red perovskite LEDs. 相似文献
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Improving the Stability and Performance of Perovskite Light‐Emitting Diodes by Thermal Annealing Treatment 下载免费PDF全文
Jae Choul Yu Dae Woo Kim Da Bin Kim Eui Dae Jung Jong Hyun Park Ah‐Young Lee Bo Ram Lee Daniele Di Nuzzo Richard H. Friend Myoung Hoon Song 《Advanced materials (Deerfield Beach, Fla.)》2016,28(32):6906-6913
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Juanhong Wang Chen Song Zhiwei He Chaohuang Mai Gancheng Xie Lan Mu Yangke Cun Jiali Li Jian Wang Junbiao Peng Yong Cao 《Advanced materials (Deerfield Beach, Fla.)》2018,30(39)
All‐solution‐processed pure formamidinium‐based perovskite light‐emitting diodes (PeLEDs) with record performance are successfully realized. It is found that the FAPbBr3 device is hole dominant. To achieve charge carrier balance, on the anode side, PEDOT:PSS 8000 is employed as the hole injection layer, replacing PEDOT:PSS 4083 to suppress the hole current. On the cathode side, the solution‐processed ZnO nanoparticle (NP) is used as the electron injection layer in regular PeLEDs to improve the electron current. With the smallest ZnO NPs (2.9 nm) as electron injection layer (EIL), the solution‐processed PeLED exhibits a highest forward viewing power efficiency of 22.3 lm W?1, a peak current efficiency of 21.3 cd A?1, and an external quantum efficiency of 4.66%. The maximum brightness reaches a record 1.09 × 105 cd m?2. A record lifetime T50 of 436 s is achieved at the initial brightness of 10 000 cd m?2. Not only do PEDOT:PSS 8000 HIL and ZnO NPs EIL modulate the injected charge carriers to reach charge balance, but also they prevent the exciton quenching at the interface between the charge injection layer and the light emission layer. The subbandgap turn‐on voltage is attributed to Auger‐assisted energy up‐conversion process. 相似文献
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Enhanced Optical and Electrical Properties of Polymer‐Assisted All‐Inorganic Perovskites for Light‐Emitting Diodes 下载免费PDF全文
Yichuan Ling Yu Tian Xi Wang Jamie C. Wang Javon M. Knox Fernando Perez‐Orive Yijun Du Lei Tan Kenneth Hanson Biwu Ma Hanwei Gao 《Advanced materials (Deerfield Beach, Fla.)》2016,28(40):8983-8989
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Lianghui Gu Kaichuan Wen Qiming Peng Wei Huang Jianpu Wang 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(30)
Perovskite light‐emitting diodes (PeLEDs) have attracted considerable attention because of their potential in display and lighting applications. To promote commercialization of PeLEDs, it is important to improve the external quantum efficiency of the devices, which depends on their internal quantum efficiency (IQE) and light extraction efficiency. Optical simulations have revealed that 20–50% of the light generated in the device will be lost to surface plasmon (SP) modes formed in the metal/dielectric interfaces. Therefore, extracting the optical energy in SP modes to the air will greatly increase the light extraction efficiency of PeLEDs. In addition, the SPs can accelerate radiative recombination of the emitter via near‐field effects. Thus, the IQE of a PeLED can also be enhanced by SP manipulation. In this review, first, general concepts of the SPs and how they can enhance the efficiency of LEDs are introduced. Then recent progresses in SP‐enhanced emission of perovskite films and LEDs are systematically reviewed. After that, the challenges and opportunities of the SP‐enhanced PeLEDs are shown, followed by an outlook of further development of the SPs in perovskite optoelectronic devices. 相似文献
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Yang Shen Li‐Peng Cheng Yan‐Qing Li Wei Li Jing‐De Chen Shuit‐Tong Lee Jian‐Xin Tang 《Advanced materials (Deerfield Beach, Fla.)》2019,31(24)
Perovskite light‐emitting diodes (PeLEDs) show great application potential in high‐quality flat‐panel displays and solid‐state lighting due to their steadily improved efficiency, tunable colors, narrow emission peak, and easy solution‐processing capability. However, because of high optical confinement and nonradiative charge recombination during electron–photon conversion, the highest reported efficiency of PeLEDs remains far behind that of their conventional counterparts, such as inorganic LEDs, organic LEDs, and quantum‐dot LEDs. Here a facile route is demonstrated by adopting bioinspired moth‐eye nanostructures at the front electrode/perovskite interface to enhance the outcoupling efficiency of waveguided light in PeLEDs. As a result, the maximum external quantum efficiency and current efficiency of the modified cesium lead bromide (CsPbBr3) green‐emitting PeLEDs are improved to 20.3% and 61.9 cd A?1, while retaining spectral and angular independence. Further reducing light loss in the substrate mode using a half‐ball lens, efficiencies of 28.2% and 88.7 cd A?1 are achieved, which represent the highest values reported to date for PeLEDs. These results represent a substantial step toward achieving practical applications of PeLEDs. 相似文献
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High‐Efficiency Solution‐Processed Inorganic Metal Halide Perovskite Light‐Emitting Diodes 下载免费PDF全文
Himchan Cho Christoph Wolf Joo Sung Kim Hyung Joong Yun Jong Seong Bae Hobeom Kim Jung‐Min Heo Soyeong Ahn Tae‐Woo Lee 《Advanced materials (Deerfield Beach, Fla.)》2017,29(31)
This paper reports highly bright and efficient CsPbBr3 perovskite light‐emitting diodes (PeLEDs) fabricated by simple one‐step spin‐coating of uniform CsPbBr3 polycrystalline layers on a self‐organized buffer hole injection layer and stoichiometry‐controlled CsPbBr3 precursor solutions with an optimized concentration. The PeLEDs have maximum current efficiency of 5.39 cd A?1 and maximum luminance of 13752 cd m?2. This paper also investigates the origin of current hysteresis, which can be ascribed to migration of Br? anions. Temperature dependence of the electroluminescence (EL) spectrum is measured and the origins of decreased spectrum area, spectral blue‐shift, and linewidth broadening are analyzed systematically with the activation energies, and are related with Br? anion migration, thermal dissociation of excitons, thermal expansion, and electron–phonon interaction. This work provides simple ways to improve the efficiency and brightness of all‐inorganic polycrystalline PeLEDs and improves understanding of temperature‐dependent ion migration and EL properties in inorganic PeLEDs. 相似文献
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Highly Efficient Perovskite Nanocrystal Light‐Emitting Diodes Enabled by a Universal Crosslinking Method 下载免费PDF全文
Guangru Li Florencia Wisnivesky Rocca Rivarola Nathaniel J. L. K. Davis Sai Bai Tom C. Jellicoe Francisco de la Peña Shaocong Hou Caterina Ducati Feng Gao Richard H. Friend Neil C. Greenham Zhi‐Kuang Tan 《Advanced materials (Deerfield Beach, Fla.)》2016,28(18):3528-3534
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Sohee Jeon Lianfeng Zhao Young‐Jin Jung Ji Whan Kim Sei‐Yong Kim Hyeokjung Kang Jun‐Ho Jeong Barry P. Rand Jeong‐Hwan Lee 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(8)
Organic–inorganic hybrid perovskite light‐emitting diodes (PeLEDs) are promising for next‐generation optoelectronic devices due to their potential to achieve high color purity, efficiency, and brightness. Although the external quantum efficiency (EQE) of PeLEDs has recently surpassed 20%, various strategies are being pursued to increase EQE further and reduce the EQE gap compared to other LED technologies. A key point to further boost EQE of PeLEDs is linked to the high refractive index of the perovskite emissive layer, leading to optical losses of more than 70% of emitted photons. Here, it is demonstrated that a randomly distributed nanohole array with high‐index contrast can effectively enhance outcoupling efficiency in PeLEDs. Based on a comprehensive optical analysis on the perovskite thin film and outcoupling structure, it is confirmed that the nanohole array effectively distributes light into the substrate for improved outcoupling, allowing for 1.64 times higher light extraction. As a result, highly efficient red/near‐infrared PeLEDs with a peak EQE of 14.6% are demonstrated. 相似文献