Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 46
·16682-16692
·
IF 7.393
Xiao-Yi Cai,Yi Yu,Yong-Chun Ye,Yang Shen,Ming-Lei Guo,Jing-Kun Wang,Kong-Chao Shen,Yan-Qing Li,Jian-Xin Tang
Metal halide perovskite light-emitting diodes (PeLEDs) have been recognized as emerging candidates for next-generation solution-processed electronic display technology, and great progress has been made in recent years. However, their poor operational stability is yet to be solved. Here, we present a reformative all-inorganic red-emission PeLED based on the passivation effect caused by the incorporation of zinc ions into perovskites for enhancing the efficiency and operational stability. A high-quality quasi-two-dimensional perovskite CsPbI3−xBrx thin film with good crystallinity is obtained, benefiting from the combination of large organic ammonium ions (PEA+ ions) and inorganic salt zinc iodide (ZnI2). As a result, ZnI2-passivated CsPbI3−xBrx PeLEDs emitting at 666 nm show a maximum external quantum efficiency of 9.93% and a maximum brightness of 4258 cd m−2. More importantly, the PeLEDs achieve a long half-lifetime of about 2667 h at an initial luminance of 100 cd m−2. This work provides a facile method to obtain stable and efficient red-emission PeLEDs.
研究领域:
材料科学
·
光电子学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Jingcong Hu,Chenghao Bi,Xuetao Zhang,Bohai Tian,Yue Lu,Jianjun Tian,Manling Sui
With the rapid development of all-inorganic CsPbX 3 (X = I, Br, and Cl) perovskite light-emitting diodes (PeLEDs), their external quantum efficiency (EQE) has made great progress in the last few years. However, severe performance degradation at the operation condition impedes its large-scale industrial application. In this text, by using the advanced spherical aberration corrected transmission electron microscope (TEM), the degradation pathway of PeLEDs under bias loading was more systematically and comprehensively, especially from the viewpoint of its microstructural evolution pathway, which showed that iodine vacancy migration triggered the structural collapse was the primary inducement of performance decay. To solve this problem, inorganic termination ZnI 2 was employed to passivate the surface halide vacancy defects and supplement the halide ion into the lattice, which significantly improves the photoluminescence (PL) lifetime and stability of CsPbI 3 quantum dots (QDs). As expected, not only the EQE of PeLEDs has been greatly improved, but also the operating half-lifetime is enhanced by about 4 times as compared with the original one. Microstructural characterization and density functional (DFT) calculations confirm that the preferential segregation of Zn element on the surface of QDs was the principal cause to passivate the defect state of QDs, which exhibits lower formation energy and better operational stability.
研究领域:
材料科学
·
光子学
·
半导体物理
✓ 已验证
DOI
高影响因子
ADVANCED MATERIALS
·
2024
·
IF 27.4
Xinwen Sun,Weiwei Meng,Kwan Ho Ngai,Zhiguo Nie,Chuhao Luan,Wenjun Zhang,Shiang Li,Xinhui Lu,Bo Wu,Guofu Zhou,Mingzhu Long,Jianbin Xu
Suppressing trap-assisted nonradiative losses through passivators is a prerequisite for efficient perovskite light-emitting diodes (PeLEDs). However, the complex bonding between passivators and perovskites severely suppresses the passivation process, which still lacks comprehensive understanding. Herein, the number, category, and degree of bonds between different functional groups and the perovskite are quantitatively assessed to study the passivation dynamics. Functional groups with high electrostatic potential and large steric hindrance prioritize strong bonding with organic cations and halides on the perfect surface, leading to suppressed coordination with bulky defects. By modulating the binding priorities and coordination capacity, hindrance from the intense interaction with perfect perovskite is significantly reduced, leading to a more direct passivation process. Consequently, the near-infrared PeLED without external light out-coupling demonstrates a record external quantum efficiency of 24.3% at a current density of 42 mA cm −2 . In addition, the device exhibits a record-level-cycle ON/OFF switching of 20 000 and ultralong half-lifetime of 1126.3 h under 5 mA cm −2 . An in-depth understanding of the passivators can offer new insights into the development of high-performance PeLEDs.
研究领域:
材料科学
·
光电子学
·
半导体物理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Applied Materials Today
·
2022
·
IF 8.663
Xikang Yang,Anlang Wu,Zhiqiang Deng,Zhihai Wu,Zhenfu Zhao,Ziyang Hu
Perovskite quantum dots (PeQDs) are emerging as one of the most promising candidates for next-generation display technology due to their outstanding optical and electrical properties. However, the inherent instability, lead-toxicity and poor electrical conductivity of PeQDs films have seriously hindered their commercial applications. To solve these problems, we adopted the strategy of Zr ions doping and in-situ passivation of CsPbBr 3 PeQDs with the short-chain inorganic ligand potassium thiocyanate (KSCN), which not only enhanced the stability and boosted the photoluminescence quantum yield (PLQY) of PeQDs films, but also improved their electrical conductivity. To further solve the problem of charge injection balance and improve the operating lifetime of the devices, we simultaneously used all-inorganic metal oxide semiconductor materials Mg-doped ZnO (Mg-ZnO) and Mg-doped NiO x (Mg-NiO x ) as the electron and hole transport layers of QLEDs (ETL and HTL), respectively. The operating stability of the devices was greatly improved while being able to withstand higher current densities. Therefore, using Zr-doped and KSCN passivated CsPbBr 3 (Zr doped CsPbBr 3 -KSCN) PeQDs as the light-emitting layer, we fabricated highly efficient and stable green-light all-inorganic quantum dots light-emitting diodes (QLEDs) with the maximum external quantum efficiency (EQE) of 13.8% and the maximum brightness of 24800 cd/m 2 . These green perovskite QLEDs provide a working half-life of 360 min (initial brightness is 1000 cd/m 2 ) and the operating half-life of the devices is more than two times higher than that of the reference devices. Our proposed strategy based on doping and in-situ inorganic ligand passivation will open a new avenue for fabricating efficient, stable and other colored perovskite QLEDs.
研究领域:
材料科学
·
电气工程
·
光电技术
✓ 已验证
DOI
高影响因子
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