共查询到20条相似文献，搜索用时 250 毫秒
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Yue Shi Yuan Fu Zhiwei Ma Dianlong Zhao Kai Wang Guanjun Xiao Bo Zou 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(21):2300455
Copper(I)-based halides have recently attracted increasing attention as a substitute for lead halides, owing to their nontoxicity, abundance, unique structure, and optoelectric properties. However, exploring an effective strategy to further improve their optical activities and revealing structure−optical property relationships still remain a great concern. Here, by using high pressure technique, a remarkable enhancement of self-trapped exciton (STE) emission associated with the energy exchange between multiple self-trapped states in zero-dimensional lead-free halide Cs3Cu2I5 NCs is successfully achieved. Furthermore, high-pressure processing endows the piezochromism of Cs3Cu2I5 NCs by experiencing a white light and a strong purple light emission, which is able to be stabilized at near-ambient pressure. The distortion of [Cu2I5] clusters composing of tetrahedral [CuI4] and trigonal planar [CuI3] and the decreased Cu–Cu distance between the adjacent Cu-I tetrahedron and triangle are responsible for the significant STEs emission enhancement under high pressure. The experiments combined with first-principles calculations not only shed light on the structure−optical property relationships of [Cu2I5] clusters halide, but also provide guidance for improving emission intensity that is highly desirable in solid-state lighting applications. 相似文献
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Jian Chen Xin Pan Xuanyu Zhang Chen Sun Congcong Chen Xiaoqin Ji Rui Chen Lingling Mao 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(25):2300938
Chiral organic−inorganic hybrid metal halide materials have shown great potential for circularly polarized luminescence (CPL) related applications for their tunable structures and efficient emissions. Here, this work combines the highly emissive Cu4I4 cubane cluster with chiral organic ligand R/S-3-quinuclidinol, to construct a new type of 1D Cu-I chains, namely Cu4I4(R/S-3-quinuclidinol)3, crystallizing in noncentrosymmetric monoclinic P21 space group. These enantiomorphic hybrids exhibit long-term stability and show bright yellow emission with a photoluminescence quantum yield (PLQY) close to 100%. Due to the successful chirality transfer from the chiral ligands to the inorganic backbone, the enantiomers show intriguing chiroptical properties, such as circular dichroism (CD) and CPL. The CPL dissymmetry factor (glum) is measured to be ≈4 × 10−3. Time-resolved photoluminescence (PL) measurements show long averaged decay lifetime up to 10 µs. The structural details within the Cu4I4 reveal the chiral nature of these basic building units, which are significantly different than in the achiral case. This discovery provides new structural insights for the design of high performance CPL materials and their applications in light emitting devices. 相似文献
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Shape control of doped semiconductor nanocrystals (d-dots) 总被引：1，自引：0，他引：1
Ranjani Viswanatha David M. Battaglia Mark E. Curtis Tetsuya D. Mishima Matthew B. Johnson Xiaogang Peng 《Nano Research》2008,1(2):138-144
Formation of Mn2+-doped ZnSe quantum dots (Mn:ZnSe d-dots) with both branched and nearly spherical shapes has been studied. Structure analysis
indicates that the Mn2+ dopants were localized in the core of a branched nanocrystal. The growth of branched d-dots, rather than spherical ones,
was achieved by simply varying the concentration of two organic additives, fatty acids, and fatty amines. The photoluminescence
properties of the branched nanocrystals were explored and compared with those of the nearly spherical particles.
Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
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Xiuwen Xu Yue-Min Xie Huaiyao Shi Yongquan Wang Xianjun Zhu Bing-Xiang Li Shujuan Liu Bing Chen Qiang Zhao 《Advanced materials (Deerfield Beach, Fla.)》2024,36(3):2303738
The ever-growing need to inspect matter with hyperfine structures requires a revolution in current scintillation detectors, and the innovation of scintillators is revived with luminescent metal halides entering the scene. Notably, for any scintillator, two fundamental issues arise: Which kind of material is suitable and in what form should the material exist? The answer to the former question involves the sequence of certain atoms into specific crystal structures that facilitate the conversion of X-ray into light, whereas the answer to the latter involves assembling these crystallites into particular material forms that can guide light propagation toward its corresponding pixel detector. Despite their equal importance, efforts are overwhelmingly devoted to improving the X-ray-to-light conversion, while the material-form-associated light propagation, which determines the optical signal collected for X-ray imaging, is largely overlooked. This perspective critically correlates the reported spatial resolution with the light-propagation behavior in each form of metal halides, combing the designing rules for their future development. 相似文献
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Renjing Xu Jiong Yang Ye Win Myint Jiajie Pei Han Yan Fan Wang Yuerui Lu 《Advanced materials (Deerfield Beach, Fla.)》2016,28(18):3493-3498
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Alkyl‐terminated silicon nanocrystals (Si NCs) are synthesized at room temperature by hydride reduction of silicon tetrachloride (SiCl4) within inverse micelles. Highly monodisperse Si nanocrystals with average diameters ranging from 2 to 6 nm are produced by variation of the cationic quaternary ammonium salts used to form the inverse micelles. Transmission electron microscopy imaging shows that the NCs are highly crystalline, while FTIR spectra confirm that the NCs are passivated by covalent attachment of alkanes, with minimal surface oxidation. UV‐vis absorbance and photoluminescence spectroscopy show significant quantum confinement effects, with moderate absorption in the UV spectral range, and a strong blue emission with a marked dependency on excitation wavelength. The photoluminescence quantum yield (Φ) of the Si NCs exhibits an inverse relationship with the mean NC diameter, with a maximum of 12% recorded for 2 nm NCs. 相似文献
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Philipp Stadler Shaimaa A. Mohamed Jacek Gasiorowski Mykhailo Sytnyk Sergii Yakunin Markus C. Scharber Christina Enengl Sandra Enengl Daniel A. M. Egbe Mabrouk K. El‐Mansy Salah S. A. Obayya N. Serdar Sariciftci Kurt Hingerl Wolfgang Heiss 《Advanced materials (Deerfield Beach, Fla.)》2015,27(9):1533-1539
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Haitao Tang;Zhenglin Jia;Yalun Xu;Yong Liu;Qianqian Lin; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(4):2304336
Recently, metal 1halide perovskites have shown compelling optoelectronic properties for both light-emitting devices and scintillation of ionizing radiation. However, conventional lead-based metal halide perovskites are still suffering from poor material stability and relatively low X-ray light yield. This work reports cadmium-based all-inorganic metal halides and systematically investigates the influence of the metal ion incorporation on the optoelectronic properties. This work introduces the bi-metal ion incorporation strategy and successfully enhances the photoluminescence quantum yield (98.9%), improves thermal stability, and extends the photoluminescence spectra, which show great potential for white light emission. In addition, the photoluminescent decay is also modulated with single metal ion incorporation, the charge carrier lifetime is successfully reduced to less than 1 µs, and the high luminescent efficiency and X-ray light yield (41 000 photons MeV−1) are maintained. Then, these fast scintillators are demonstrated for high-speed light communication and sensitive X-ray detection and imaging. 相似文献
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Zhishan Luo Qian Li Liming Zhang Xiaotong Wu Li Tan Chao Zou Yejing Liu Zewei Quan 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(3)
0D lead‐free metal halide nanocrystals (NCs) are an emerging class of materials with intriguing optical properties. Herein, colloidal synthetic routes are presented for the production of 0D Cs3Cu2X5 (X = I, Br, and Cl) NCs with orthorhombic structure and well‐defined morphologies. All these Cs3Cu2X5 NCs exhibit broadband blue‐green photoluminescence (PL) emissions in the range of 445–527 nm with large Stokes shifts, which are attributed to their intrinsic self‐trapped exciton (STE) emission characteristics. The high PL quantum yield of 48.7% is obtained from Cs3Cu2Cl5 NCs, while Cs3Cu2I5 NCs exhibit considerable air stability over 45 days. Intriguingly, as X is changed from I to Br and Cl, Cs3Cu2X5 NCs exhibit a continuous redshift of emission peaks, which is contrary to the blueshift in CsPbX3 perovskite NCs. 相似文献
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Jiangwei Li Takeshi Inoshita Tianping Ying Atsushi Ooishi Junghwan Kim Hideo Hosono 《Advanced materials (Deerfield Beach, Fla.)》2020,32(37):2002945
In the field of photonics, alkali copper(I) halides attract considerable attention as lead-free emitters. The intrinsic quantum confinement effects originating from low-dimensional electronic structure lead to high photoluminescence quantum yields (PLQYs). Among them, Cs3Cu2I5 is the most promising candidate, satisfying both high PLQY and air stability. In this study, a strategy to explore a new material meeting these requirements through the use of the mixed-anions of I− and Cl− is proposed. The expectation is maintained that the large difference in ionic radii between them likely results in the formation of a novel compound. Consequently, Cs5Cu3Cl6I2 with a 1D zigzag chain structure is discovered. This material exhibits blue emission (≈462 nm) with a near-unity quantum yield of 95%. An electronic structure calculation reveals that the localized nature of the valence band maximum is crucial in obtaining efficient self-trapped exciton emission. Moreover, the iodine-bridged 1D connectivity significantly enhances the chemical stability of Cs5Cu3Cl6I2, compared with the pure chloride phase. The present findings provide a new perspective for developing air-stable alkali copper(I) halides with highly efficient luminescence. 相似文献
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《Advanced Materials Interfaces》2018,5(13)
There are various efforts to tailor the excitonic properties in monolayer transition metal dichalcogenides (TMDs) for exploring their potential applications in optoelectronic devices. However, the low quantum yields (QYs), despite their direct bandgap nature, have limited the application in much fields. Encouragingly, excitons combined with defects endow WS2 quantum dots (QDs) with certain desirable properties through strain engineering. A strong exciton photoluminescence (PL) of WS2 QDs even up to ≈20 GPa by PL measurements is reported. Their PL reveals that a distinct defect‐induced peak D is located below the neutral exciton peak A. This peak D originates from defect‐bound excitons and intensifies with increasing pressure as more electrons transfer from WS2 QDs to O2. In addition, a transition from direct to indirect bandgap above 4.5 GPa is revealed by both experimental measurements and theoretical calculations. The evolution of electronic structure is related to lattice structural distortion. The results provide a new direction for modulating the optical properties of TMDs QDs through utilizing defects–excitons interactions. The pressure‐tuned emission of excitons combined with strong PL from defects sites of WS2 QDs may have promising applications in optoelectronic devices. 相似文献
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