Advanced Science
·
2019
·Vol. 6
·期 13
·1900462
·
IF 15.804
Chenghao Bi,Shixun Wang,Stephen V. Kershaw,Kaibo Zheng,Tönu Pullerits,Sergey Gaponenko,Jianjun Tian,Andrey L. Rogach
Colloidal all-inorganic perovskite nanocrystals have gained significant attention as a promising material for both fundamental and applied research due to their excellent emission properties. However, reported photoluminescence quantum yields (PL QYs) of blue-emitting perovskite nanocrystals are rather low, mostly due to the fact that the high energy excitons for such wide bandgap materials are easily captured by interband traps, and then decay nonradiatively. In this work, it is demonstrated how to tackle this issue, performing self-assembly of 2D perovskite nanoplatelets into larger size (≈50 nm × 50 nm × 20 nm) cuboid crystals. In these structures, 2D nanoplatelets being isolated from each other within the cuboidal scaffold by organic ligands constitute multiple quantum wells, where exciton localization on potential disorder sites helps them to bypass nonradiative channels present in other platelets. As a result, the cuboid crystals show an extremely high PL QY of 91% of the emission band centered at 480 nm. Moreover, using the same synthetic method, mixed-anion CsPb(Br/Cl) 3 cuboid crystals with blue emission peaks ranging from 452 to 470 nm, and still high PL QYs in the range of 72–83% are produced.
研究领域:
材料科学
·
纳米科技
·
光电子学
·
半导体物理
·
胶体化学
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2019
·Vol. 7
·期 20
·1900774
·
IF 7.125
Xin Zhang,Dengbao Han,Chenhui Wang,Imran Muhammad,Feng Zhang,Ali Shmshad,Xulan Xue,Wenyu Ji,Shuai Chang,Haizheng Zhong
The in situ fabricated perovskite nanocrystals (PNCs) obtained through spin-coating a precursor solution are suitable candidates to achieve efficient perovskite light emitting diodes (PeLEDs). In this work, the solvent effects of on-chip crystallization are investigated by correlating the nucleation and growth process of in situ fabricated formamidinium lead iodide (FAPbI 3 ) nanocrystals with their optical and electronic properties. The FAPbI 3 nanocrystals obtained from a precursor solution in γ-butyrolactone (GBL) are smaller than those obtained from N , N -dimethylformamide and dimethyl sulfoxide, and the relatively weak coordination between GBL and the precursor molecules enables reduced defect states in the resulted PNCs with enhanced photoluminescence properties. A modified LaMer model is proposed to describe the solvent effects in the on-chip crystallization process. Based on these understandings, red emissive FA 0.87 Cs 0.13 PbI 3 nanocrystal films with absolute photoluminescence quantum yields up to 70% are realized. Finally, an efficient PeLED with maximum luminance of 218 cd m −2 and peak external quantum efficiency of 15.8% is achieved with good reproducibility.
研究领域:
材料科学
·
纳米科技
·
光电子学
·
半导体器件
·
凝聚态物理
✓ 已验证
DOI
高影响因子
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
·
2023
·Vol. 40
·期 8
·2300032
·
IF 2.7
Hao Jiang,Chenxi Zang,Yixiu Dong,Min Lai,Shuhong Xu,Jingkun Xu
CsPbX 3 (X = Cl, Br, I) nanocrystals (NCs) are competitive materials for a wide range of applications because of their outstanding optoelectronic properties. Ion doping has been demonstrated as one powerful method for improving the optical properties of CsPbX 3 NCs. However, the conventional ion-doping approaches are tedious, and generally performed under an inert atmosphere and high temperature. In this work, a one-step ultrasonic-assisted approach is demonstrated to prepare doped CsPbX 3 NCs. To demonstrate the universality of the ultrasonic-assisted ion-doping approach, three ion-doped perovskite NCs are prepared, which represent three common improvements effects of ion doping on perovskite NCs, namely improved stability, PL emission, and photoluminescence quantum yields (PLQYs) of perovskite NCs. Sr-doped CsPbI 3 NCs showed improved phase stability. Mn-doped CsPbCl 3 NCs showed dual-color emissions at 406 and 580 nm. The PLQYs of the as-prepared Ni-doped CsPbCl 3 NCs are greatly improved, from 10.1% to 71%. Such a simple and versatile ion-doping approach may promote the practical applications of all-inorganic perovskite NCs.
研究领域:
材料科学
·
纳米技术
·
光电子学
·
无机化学
·
半导体材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Decai Huang,Sisi Liang,Dejian Chen,Jie Hu,Kunyuan Xu,Haomiao Zhu
The emerging applications of near-infrared (NIR) spectroscopy technology in medicine and food security call for compact and efficient NIR light source such as NIR phosphor converted LEDs (pc-LED). Currently, most of the NIR phosphors suffer from low photoluminescence (PL) quantum yield and poor thermal or chemical stability. Herein, a fluoride garnet NIR Na 3 Al 2 Li 3 F 12 :Cr 3+ phosphor was successfully synthesized via coprecipitation method. It can be excited efficiently by blue or red light and shows a broad emission band covering 650–1000 nm (bandwidth of ~110 nm) with a PL quantum yield of 78%. The fine electronic structure of Cr 3+ ions in the host was revealed by the measurement of temperature-dependent (8–300 K) excitation and emission spectra analysis. Particularly, at 423 K, the Na 3 Al 2 Li 3 F 12 :5%Cr 3+ sample retained ~99% of the PL intensity at room temperature, exhibiting excellent PL thermal stability. A NIR pc-LED was fabricated by combining the Na 3 Al 2 Li 3 F 12 :5%Cr 3+ phosphor with a commercial blue LED chip, and radiant flux of 14.3 mW in NIR region was obtained at 60 mA drive current. Furthermore, the penetration of NIR light generated by this pc-LED in chicken breast was reached. The results suggested that Na 3 Al 2 Li 3 F 12 :Cr 3+ is a promising candidate for broadband pc-LED in NIR spectroscopy applications.
研究领域:
材料科学
·
光学工程
·
生物医学光子学
·
半导体器件
·
分析化学
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2023
·Vol. 11
·期 22
·2300888
·
IF 9
Bihao Zhuang,Zicong Jin,Jiahuan Deng,Hui Xiong,Wenzhe Li,Jiandong Fan
Organic-inorganic hybrid metal halide perovskite has played an important role in optoelectronics and photonics due to their extremely high photoluminescence quantum yield (PLQY). However, considering the strong nonmetallic property of antimony (Sb), the excitons in antimony-based single crystals are usually dissipated in the form of non-radiative recombination under organic-inductive effect, which leads to the low PLQY. Herein, two kinds of perovskite-like single crystals, i.e., (8-HQ) 2 SbCl 3 and (8-HQH)SbCl 4 , are innovatively grown. The density functional theory (DFT) calculations reveal that the unique luminescence characteristics are associated with the inductive effect of organic coordination and exciton effect in the metal octahedral skeleton. When Cl − replaces the organic ligand in (8-HQ) 2 SbCl 3 , the inductive effect is reduced while the self-trapped exciton effect in the metal octahedron is enhanced. Besides, the theoretical research on electron transmission in a modeling device reveals that the hydrogen bond of organic A-site in the single crystal promotes the transition of electrons. Based on the luminescent properties of (8-HQH)SbCl 4 , the white LED devices are obtained by coating (8-HQH)SbCl 4 and red phosphor on 450 nm LED chips.
研究领域:
材料科学
·
光电子学
·
凝聚态物理
·
无机化学
·
半导体器件
·
光学材料
·
晶体工程
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2022
·Vol. 10
·期 15
·2200605
·
IF 10.05
Shaofan Fang,Bo Zhou,Huixia Li,Hanlin Hu,Haizhe Zhong,Henan Li,Yumeng Shi
Metal halide perovskites are promising optoelectronic materials due to their unique luminescent properties. However, their practical application is limited by their poor chemical stability, especially in humid environments. Moisture can cause phase changes or chemical decomposition, resulting in significant fluorescence quenching. In this study, a copper-based organic–inorganic hybrid metal halide (t-BA) 3 Cu 6 I 9 is synthesized (t-BA + is the tert-butyl-ammonium ion (C(CH 3 ) 3 NH 3 + )). This material exhibits water-induced luminescence, and its chemical stability in humid environments is being investigated. Tetragonal t-BA 3 Cu 6 I 9 is not luminescent, but it reacts quickly with water in the air. The resultant (t-BA) 2 Cu 2 I 4 ·H 2 O has a broad green emission peak at 520 nm, high photoluminescence quantum yield of 59.4%. Remarkably, (t-BA) 2 Cu 2 I 4 ·H 2 O is converted back to t-BA 3 Cu 6 I 9 at temperatures above 40 °C. This phase conversion is highly repeatable, and the luminescent intensity can be fully recovered after 50 transformation cycles. The mechanism of luminescence is investigated through temperature-dependent photoluminescence spectra and theoretical calculation, which suggests that (t-BA) 2 Cu 2 I 4 ·H 2 O has a more localized charge distribution and sufficient polyhedral distortion, resulting in a bright and efficient emission from self-trapped excitons. This is the first report of water-induced luminescence in copper-based metal halides, and it paves the way for stable luminescent materials that are responsive to humidity.
研究领域:
材料化学
·
光物理学
·
无机化学
·
功能材料
·
发光材料
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2018
·Vol. 28
·期 34
·1802848
·
IF 13.325
Zhenguang Wang,Yu-e Shi,Xuming Yang,Yuan Xiong,Yanxiu Li,Bingkun Chen,Wing-Fu Lai,Andrey L. Rogach
A water-soluble, positively charged polymer is obtained by copolymerizing chitosan with hypromellose, and the evaluation of its biocompatibility and the capacity for the loading of exogenous agents is performed. Films based on hypromellose grafted chitosan (HGC) are employed as a matrix to fabricate composite films by dehydration-triggered aggregation of copper nanoclusters (NCs). The resulting HGC/Cu NC films are transparent and exhibit an aggregation-induced emission enhancement of copper NCs, with a resulting photoluminescence quantum yield of 42%. The application of these orange emitting films as color converters for fabrication of remote light-emitting devices is demonstrated.
研究领域:
高分子科学
·
生物材料
·
纳米医学
·
药物递送
·
光电子学
·
生物医学工程
·
荧光成像
·
转化医学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）