scholarly journals Hard and soft Lewis-base behavior for efficient and stable CsPbBr3 perovskite light-emitting diodes

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Changjiu Sun ◽  
Junli Wei ◽  
Jian Zhao ◽  
Yuanzhi Jiang ◽  
Yilong Wang ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Surface Defects ◽  
Lewis Base ◽  
Defect States ◽  
Light Emitting ◽  
Lewis Bases ◽  
Molecule Design ◽  
Electron Withdrawing Group ◽  
Powerful Electron

Abstract All-inorganic CsPbBr3 perovskite is an attractive emission material for high-stability perovskite light-emitting diodes (PeLEDs), due to the high thermal and chemical stability. However, the external quantum efficiencies (EQEs) of CsPbBr3 based PeLEDs are still far behind their organic–inorganic congeners. Massive defect states on the surface of CsPbBr3 perovskite grains should be the main reason. Lewis base additives have been widely used to passivate surface defects. However, systematic investigations which relate to improving the passivation effect via rational molecule design are still lacking. Here, we demonstrate that the CsPbBr3 film’s optical and electrical properties can be significantly boosted by tailoring the hardness–softness of the Lewis base additives. Three carboxylate Lewis bases with different tail groups are selected to in-situ passivate CsPbBr3 perovskite films. Our research indicates that 4-(trifluoromethyl) benzoate acid anion (TBA−) with the powerful electron-withdrawing group trifluoromethyl and benzene ring possesses the softest COO− bonding head. TBA− thus acts as a soft Lewis base and possesses a robust combination with unsaturated lead atoms caused by halogen vacancies. Based on this, the all-inorganic CsPbBr3 PeLEDs with a maximum EQE up to 16.75% and a half-lifetime over 129 h at an initial brightness of 100 cd m−2 is thus delivered.

scholarly journals Phenylalkylammonium passivation enables perovskite light emitting diodes with record high-radiance operational lifetime: the chain length matters

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuwei Guo ◽  
Sofia Apergi ◽  
Nan Li ◽  
Mengyu Chen ◽  
Chunyang Yin ◽  
...  
Keyword(s):  
Chain Length ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Surface Defects ◽  
Theoretical Modelling ◽  
Ion Migration ◽  
Light Emitting ◽  
Operational Lifetime ◽  
Chain Lengths

AbstractPerovskite light emitting diodes suffer from poor operational stability, exhibiting a rapid decay of external quantum efficiency within minutes to hours after turn-on. To address this issue, we explore surface treatment of perovskite films with phenylalkylammonium iodide molecules of varying alkyl chain lengths. Combining experimental characterization and theoretical modelling, we show that these molecules stabilize the perovskite through suppression of iodide ion migration. The stabilization effect is enhanced with increasing chain length due to the stronger binding of the molecules with the perovskite surface, as well as the increased steric hindrance to reconfiguration for accommodating ion migration. The passivation also reduces the surface defects, resulting in a high radiance and delayed roll-off of external quantum efficiency. Using the optimized passivation molecule, phenylpropylammonium iodide, we achieve devices with an efficiency of 17.5%, a radiance of 1282.8 W sr−1 m−2 and a record T50 half-lifetime of 130 h under 100 mA cm−2.

scholarly journals Dimension control of in situ fabricated CsPbClBr2 nanocrystal films toward efficient blue light-emitting diodes

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Chenhui Wang ◽  
Dengbao Han ◽  
Junhui Wang ◽  
Yingguo Yang ◽  
Xinyue Liu ◽  
...  
Keyword(s):  
Quantum Well ◽  
Light Emitting Diodes ◽  
Blue Emission ◽  
Light Emitting ◽  
Mixed Ligands ◽  
Dimension Control ◽  
Nanocrystal Films ◽  
Width Distribution ◽  
Quantum Well Width

AbstractIn the field of perovskite light-emitting diodes (PeLEDs), the performance of blue emissive electroluminescence devices lags behind the other counterparts due to the lack of fabrication methodology. Herein, we demonstrate the in situ fabrication of CsPbClBr2 nanocrystal films by using mixed ligands of 2-phenylethanamine bromide (PEABr) and 3,3-diphenylpropylamine bromide (DPPABr). PEABr dominates the formation of quasi-two-dimensional perovskites with small-n domains, while DPPABr induces the formation of large-n domains. Strong blue emission at 470 nm with a photoluminescence quantum yield up to 60% was obtained by mixing the two ligands due to the formation of a narrower quantum-well width distribution. Based on such films, efficient blue PeLEDs with a maximum external quantum efficiency of 8.8% were achieved at 473 nm. Furthermore, we illustrate that the use of dual-ligand with respective tendency of forming small-n and large-n domains is a versatile strategy to achieve narrow quantum-well width distribution for photoluminescence enhancement.

Efficiency degradation induced by surface defects-assisted tunneling recombination in GaN/InGaN micro-light-emitting diodes

2021 ◽  
Vol 118 (2) ◽  
pp. 021105
Author(s):  
Jian Yin ◽  
Ehsanollah Fathi ◽  
Hossein Zamani Siboni ◽  
Chao Xu ◽  
Dayan Ban
Keyword(s):  
Light Emitting Diodes ◽  
Surface Defects ◽  
Light Emitting ◽  
Tunneling Recombination ◽  
Assisted Tunneling

Excitonic Creation of Highly Luminescent Defects In Situ in Working Organic Light-Emitting Diodes

2017 ◽  
Vol 6 (2) ◽  
pp. 1700856 ◽  
Author(s):  
Yong-Biao Zhao ◽  
Grayson L. Ingram ◽  
Xi-Wen Gong ◽  
Xi-Yan Li ◽  
Li-Na Quan ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light

scholarly journals Suppressing the Initial Growth of Sidewall GaN by Modifying Micron-Sized Patterned Sapphire Substrate with H3PO4-Based Etchant

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 622 ◽  
Author(s):  
Wen-Yang Hsu ◽  
Yuan-Chi Lian ◽  
Pei-Yu Wu ◽  
Wei-Min Yong ◽  
Jinn-Kong Sheu ◽  
...  
Keyword(s):  
Sapphire Substrate ◽  
Light Emitting Diodes ◽  
Ex Situ ◽  
Initial Growth ◽  
Patterned Sapphire Substrate ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Patterned Sapphire Substrates

Micron-sized patterned sapphire substrates (PSS) are used to improve the performance of GaN-based light-emitting diodes (LEDs). However, the growth of GaN is initiated not only from the bottom c-plane but also from the sidewall of the micron-sized patterns. Therefore, the coalescence of these GaN crystals creates irregular voids. In this study, two kinds of nucleation layers (NL)—ex-situ AlN NL and in-situ GaN NL—were used, and the growth of sidewall GaN was successfully suppressed in both systems by modifying the micron-sized PSS surface.

In Situ Fabrication of Bendable Microscale Hexagonal Pyramids Array Vertical Light Emitting Diodes with Graphene as Stretchable Electrical Interconnects

ACS Photonics ◽  
2014 ◽  
Vol 1 (5) ◽  
pp. 421-429 ◽  
Author(s):  
Liancheng Wang ◽  
Jun Ma ◽  
Zhiqiang Liu ◽  
Xiaoyan Yi ◽  
Hongwei Zhu ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Light Emitting ◽  
In Situ Fabrication ◽  
Electrical Interconnects

scholarly journals Optical Patterning: Direct Optical Patterning of Quantum Dot Light‐Emitting Diodes via In Situ Ligand Exchange (Adv. Mater. 46/2020)

2020 ◽  
Vol 32 (46) ◽  
pp. 2070346
Author(s):  
Himchan Cho ◽  
Jia‐Ahn Pan ◽  
Haoqi Wu ◽  
Xinzheng Lan ◽  
Igor Coropceanu ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Ligand Exchange ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Optical Patterning

In Situ Ligand Bonding Management of CsPbI 3 Perovskite Quantum Dots Enables High‐Performance Photovoltaics and Red Light‐Emitting Diodes

2020 ◽  
Vol 59 (49) ◽  
pp. 22230-22237 ◽  
Author(s):  
Junwei Shi ◽  
Fangchao Li ◽  
Yan Jin ◽  
Cheng Liu ◽  
Ben Cohen‐Kleinstein ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Performance ◽  
Light Emitting Diodes ◽  
Red Light ◽  
Light Emitting ◽  
Perovskite Quantum Dots

Efficient orange-red phosphorescent organic light-emitting diodes using an in situ synthesized copper(i) complex as the emitter

2014 ◽  
Vol 2 (31) ◽  
pp. 6333-6341 ◽  
Author(s):  
Feng Wei ◽  
Jacky Qiu ◽  
Xiaochen Liu ◽  
Jianqiang Wang ◽  
Huibo Wei ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light

Orange-red phosphorescent organic light-emitting diodes with inexpensive and eco-friendly luminescent Cu(i) complexes as the emitter are successfully realized by a codeposition method

51.2: Invited Paper: Efficient Light‐emitting Diodes Based on In‐situ Fabricated Perovskite Nanocrystals

2019 ◽  
Vol 50 (S1) ◽  
pp. 567-567
Author(s):  
Dengbao Han ◽  
Muhammad Imran ◽  
Xin Zhang ◽  
Chenhui Wang ◽  
Shuai Chang ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Light Emitting ◽  
Perovskite Nanocrystals
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