ACS Applied Nano Materials
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2019
·
IF 0
Hongxiang Zhang,Chunxia Wu,Canran Zhang,Bisheng Yan,Jiyuan Guo,Gangyi Zhu,Jun Dai
In this paper, we report the dual-wavelength green-light emission from zinc oxide (ZnO)-nanoseed-decorated p-GaN (gallium nitride)/n-ZnO nanorod/CsPbBr3 quantum dots (QDs) light-emitting diodes (LEDs). At the same time, the effect of ZnO nanoseeds on the p-GaN/n-ZnO nanorod/CsPbBr3 QDs LED performance is deeply studied. ZnO nanoseeds were fabricated by magnetron sputtering and the sol–gel method; then ZnO nanorods were obtained on GaN by hydrothermal treatment to form the p-GaN/n-ZnO nanorod heterojunction, and green CsPbBr3 QDs were further deposited on ZnO nanorod arrays to realize LEDs. The results show that magnetron-sputtering ZnO nanoseeds can induce regular vertical ZnO nanorod arrays, and the corresponding device presents a better electroluminescence (EL) performance. The X-ray diffraction, atomic force microscopy, and EL mechanisms indicate that the p-GaN/n-ZnO nanorod with magnetron-sputtering ZnO nanoseeds has a better crystalline interface. Our results indicate that the p-GaN/n-ZnO nanorod/CsPbBr3 QDs heterojunction structure can be served as dual-wavelength LEDs, and magnetron-sputtering ZnO nanoseeds can give rise to a better EL performance.
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Nanoscale
·
2019
·Vol. 11
·期 36
·16852-16859
·
IF 6.97
Keqiang Chen,Yingwei Wang,Jiefeng Liu,Jianlong Kang,Yanqi Ge,Weichun Huang,Zhitao Lin,Zhinan Guo,Yupeng Zhang,Han Zhang
Zero-dimensional (0D)-2D nanostructures, which combine the efficient light-harvesting properties of 0D nanocrystals (NCs) and the ultrafast carrier transfer of 2D materials, have been widely used in optoelectronic devices. Although the most common way to fabricate 0D–2D nanostructures consists of a mixing process, the limited loading efficiency of NCs and the poor 0D–2D interface hinder the efficient photo-carrier generation and fast carrier separation/transfer in such systems. Herein, the in situ synthesis of CsPbBr3/BP heterostructures via a hot-injection method was presented, revealing that both the formation process of CsPbBr3 NCs and the CsPbBr3/black phosphorous (BP) interfaces presented pronounced changes. This led to a larger CsPbBr3 NC size, higher CsPbBr3 NC loading efficiency, optimized combination of CsPbBr3 and BP at the interface, and enhanced carrier transfer properties. In addition, the in situ synthesized CsPbBr3/BP heterostructure was used as a photoactive material for the fabrication of photodetectors, which showed high detectivity (D*) of 2.6 × 1011 Jones. This work highlights a novel strategy to optimize the 0D–2D heterostructure interface and to promote its carrier transfer efficiency, broadening the field of the applications of mixed-dimensional nanostructures.
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Nanoscale
·
2018
·Vol. 11
·期 4
·1784-1789
·
IF 7.233
Qiang Jing,Yue Xu,Yucong Su,Xing Xing,Zhenda Lu
Cs4PbBr6 nanocrystals (NCs) have been recently studied as they can enhance the light emitting efficiency and stability of CsPbBr3 NCs. However, the synthesis of Cs4PbBr6 NCs is often accompanied by the generation of CsPbBr3 NCs, and less attention has been paid to how to exactly control their formation. Here, we investigated the key factors in deciding the final products in the hot-injection synthesis by a modified amine-free method. We found that the molarity ratio of Cs/Pb dominated the final products, while the amount of bromine had a relatively small effect. In addition, introducing a certain amount of oleylamine into the amine-free reaction leads to the formation of Cs4PbBr6, instead of CsPbBr3 NCs. This clearly shows that the protection ligand oleylamine also plays an important role in the formation of Cs4PbBr6 NCs. This well understood and fine control of the synthesis may inspire a new CsPbBr3@Cs4PbBr6 core–shell structure, with the same chemical elements but a different crystal phase in the core and the shell. This nanostructure would open a new avenue for enhancing the stability of perovskite nanocrystals.
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高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Jin-Feng Liao,Yang-Fan Xu,Xu-Dong Wang,Hong-Yan Chen,Dai-Bin Kuang
Though coating CsPbBr3 nanocrystal (NC) with an outer layer has been regarded as an effective strategy to address its instability issues, deep investigations into the electronic interaction between CsPbBr3 NC and coating layer have yet to be conducted. In this study, the dynamics of hot carrier and charge carrier of CsPbBr3 nanocrystal with various MO2 (M = Si, Ti, Sn) coating layers have been comprehensively studied. Combined transient optical characterizations (time-resolved photoluminescence and ultrafast transient absorption) and photoelectrochemical measurements reveal that coating with insulating SiO2 accelerates the hot carrier relaxation and enhances the radiative recombination by passivating surface traps, whereas efficient charge-carrier separation and extraction are observed after coating with SnO2 and TiO2. The electron injection from CsPbBr3 NC to SnO2 (1.14 × 108 s–1) is 2-fold faster than to TiO2 (5.4 × 107 s–1) owing to the lower conduction band edge and the higher electron mobility of SnO2. Particularly, the first time fabricated CsPbBr3 NC/SnO2 composite exhibits superior stability against UV light and moisture, as well as the best photocurrent response in this study. This work has implied that rational design of the coating layer for perovskite NC can not only improve the stability but also tailor the electronic and optoelectronic properties for various applications.
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高影响因子
Nanoscale
·
2018
·Vol. 10
·期 48
·22766-22774
·
IF 7.233
Ruxue Li,Zhipeng Wei,Haixia Zhao,Hongrui Yu,Xuan Fang,Dan Fang,Junzi Li,Tingchao He,Rui Chen,Xiaohua Wang
All-inorganic perovskite quantum dots (QDs) have been considered as outstanding candidates for high-performance optoelectronic device applications. However, the chemical and optical stabilities restrict their device applications. In this paper, hydrophobic zeolites were proposed to modify CsPbBr3 QDs to prevent water influence while achieving good dispersion. These hybrid luminescent materials possess high internal quantum efficiency (IQE, ∼81%@3.52 W cm−2) and low dissociation levels that give rise to improved optical stability in terms of temperature and time. More interesting, it is found that this nanocomposite is able to maintain its optical limiting performance under intensive laser illumination. This paper discusses the linear and nonlinear optical characteristics of CsPbBr3 QDs, which would be of great importance for both fundamental physics investigation and practical multiphoton applications.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
·
IF 4.9
Jintao He,Chang Liu,Jianlin Chen,Yu Zou,Wenxia Ye,Ruoxi Yang,Jincheng Huang,Zhuoyin Peng,Jian Chen
Low temperature solution-processed SnO 2 is favorable for electron transport layer (ETL) of flexible perovskite solar cells (PSCs) owing to their process compatibility. Here, we propose a route of condensation reflux-processed SnO 2 ETLs for PSCs using SnCl 2 source. However, the low temperature SnCl 2 -derived SnO 2 ETLs are inherently associated with a high defect state density as well as a large amount of H + and Cl - residual on the surface, which will cause open-circuit voltage ( V OC ) loss of the devices. To tackle this issue, aqueous solutions of KOH, CsOH, and KCl have been employed to regulate the buried interfaces. The effects of different cations (K + and Cs + ) and anions (OH - and Cl - ) on the photovoltaic performance of the devices have been comparatively explored. The buried interface with KOH modification showed the best effect, which not only improved the quality and light absorption of CsPbBr 3 perovskite layer but also markedly reduced the defect state density at the interface. The optimal device with an architecture of FTO/SnO 2 /KOH/CsPbBr 3 /carbon exhibited a champion power conversion efficiency (PCE) of 7.80 %, V OC of 1.46 V, short-circuit current density ( J SC ) of 7.50 mA/cm 2 , and fill factor ( FF ) of 0.71, compared with the pristine counterpart with a PCE of 5.86 %, V OC of 1.40 V, J SC of 6.37 mA/cm 2 , and FF of 0.66, respectively. The strategy of low temperature-processed SnO 2 ETLs by KOH interface modification may also provide an avenue for other-typed flexible PSCs manufacture.
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OPTICAL MATERIALS
·
2024
·
IF 3.8
Qizheng Dong,Yuanyuan Wang,Xueyou Zhu,Ling He
Ca 2+ and Tm 3+ co-doped CsPbBr 3 @glass composites were successfully synthesized through the high-temperature melting-water quenching-heat treatment method. Enhancement of optical performance is achieved through dual doping, harnessing simultaneous influences from both the glass structure and the inherent structure of CsPbBr 3 quantum dots (QDs). The presence of Ca 2+ in the glass reduces its viscosity and enhances the precipitation of QD crystals. Concurrently, the incorporation of Tm 3+ leads to the control of dimensions and band gaps, reduction in V Br defects, and the potential creation of energy transfer pathways, thereby effectively improving the optical performance of QDs. Simultaneous co-doping with Ca 2+ circumvents the drawback of low crystallinity observed in singly Tm 3+ -doped CsPbBr 3 QDs. In contrast to the undoped sample, the photoluminescence (PL) intensity of the optimized sample demonstrated a significant increase of 128 %. The photoluminescence quantum yield (PLQY) also experienced a rise from 18 % to 55 %, while the fluorescence lifetime extended from 68 ns to 107 ns. Furthermore, the encapsulation of the borosilicate glass matrix has been shown to greatly improve the time, water, thermal, and photostability of CsPbBr 3 QDs. These remarkable properties position the Ca 2+ and Tm 3+ co-doped CsPbBr 3 QDs@glass composites as ideal materials for illumination and wide-color-gamut displays.
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ACS Applied Nano Materials
·
2024
·
IF 5.3
Rongrong Hu,Wenfang Peng,Lin Cheng,Qiaoyun Wu,Gaolei Dong,Pan Liang,Bobo Yang,Yuefeng Li,Jun Zou,Donghai Feng
Metal halide perovskite nanocrystals (NCs) are emerging for emitting applications due to their high photoluminescence (PL) quantum yield and wide PL wavelength tunability. Here, the light-induced PL enhancement in complexes of CsPbBr3 NCs and 1-octanethiol (OT) molecules (refers to below as NC–OT complexes) is investigated. In comparison with that of as-grown CsPbBr3 NCs, the PL intensity of NC–OT complexes is lower before light illumination. While after ultraviolet light illumination, the PL performance of NC–OT complexes is improved in both air and nitrogen atmospheres. Compared with air atmospheres, anaerobic atmospheres are more effective at increasing the PL intensity because of eliminating photo-oxidation. The light illumination prevents the nonradiative process and enhances the radiative emission in NC–OT complexes, supported by transient PL and photobleaching measurements, due to better surface passivation through thiol–ene reactions. The light-induced PL enhancement in NC–OT complexes provides valuable information for the applications of perovskite nanomaterial-based emitting devices.
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高影响因子
DALTON TRANSACTIONS
·
2024
·Vol. 53
·期 36
·15330-15337
·
IF 3.5
Fangzheng Qi,Zengsheng Guo,Yuhan Zhang,Xue-Na Tang,Yiqiang Sun,Bo Xu,Guang-Ning Liu,Cuncheng Li
The stable contact of heterogeneous interfaces and the substantial exposure of active sites are crucial for enhancing the photocatalytic performance of semiconductor catalysts. However, most reported two-dimensional (2D)/2D CsPbBr3 and BiOCl heterostructures are fabricated using electrostatic self-assembly methods, which exhibit significant deficiencies in precise interface quality control and effective active site exposure. In this study, we fabricate a zero-dimensional (0D)/2D CsPbBr3/BiOCl heterojunction via a two-step calcination method, achieving an efficient direct S-scheme configuration. Optimizing interfacial contact and band alignment between CsPbBr3 quantum dots and BiOCl nanosheets enhances cross-plane charge transfer, promoting superior charge separation. This 0D/2D CsPbBr3/BiOCl heterojunction exhibits enhanced carrier mobility and high conversion rates without cocatalysts or sacrificial agents. The mechanism underlying the accelerated S-scheme charge transfer is comprehensively elucidated through a combination of analytical techniques and density functional theory (DFT) calculations. This study offers a novel approach for managing charge carrier segregation and mobility in CO2 reduction photocatalysts.
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2024
·Vol. 48
·期 26
·11688-11696
·
IF 2.7
Han Wang,WenJing Gao,Yangjie Li,Yang He,Haihu Yu
Cesium lead halide (CsPbX3, X = Cl, Br, and I) perovskite nanocrystals (PNCs) have become attractive materials for fluorescence sensing in recent years due to their excellent photoluminescent properties. Because of their ionic properties, PNCs are unstable in polar solvents, making it difficult for them to detect substances in water. Some methods are useful, such as non-homogeneous phase sensing and wrapping an inert layer around the surface of PNCs. However, these methods reduce the sensing efficiency and hinder the interaction of PNCs with sensing substances. In addition, the encapsulated PNCs are more likely to undergo fluorescence quenching and decreased storage stability. In this work, (3-aminopropyl)trimethoxysilane (APTMS) was used to synthesize APTMS PNCs (A-PNCs) by a hot injection one-pot method, and they exhibited satisfactory fluorescence properties, stability, and monodispersity. By introducing ethanol to form a water–ethanol–hexane homogeneous system, the A-PNCs were able to increase their anion-exchange capacity after directly interacting with chloride ions (Cl−) in water. Based on the fluorescence wavelength variation of the A-PNCs, testing for Cl− in human sweat was accomplished in 1 minute, with the advantages of fast speed, high precision, and satisfactory stability. On this basis, the reacted A-PNCs were immobilized on the film with bright fluorescence and color stability, and their tricolor (RGB) values were extracted for visual sensing. Thus, well-dispersed A-PNCs in hexane can rapidly detect chloride ions in water, which will enhance the application of perovskite materials for sensing in polar solvents.
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Journal of Physical Chemistry C
·
2024
·
IF 3.3
Shipei Sun,Peng Huang,Xian-gang Wu,Cuili Chen,Xiangmin Hu,Zelong Bai,Anatoly Pushkarev,Haizheng Zhong
The ligand exchange of perovskite nanocrystals is crucial for achieving highly efficient and stable light-emitting diodes (PeLEDs). Here, we report the shape transformation of CsPbBr3 nanocrystals from dodecahedron to cube during the ligand exchange using dimethylammonium bromide (DDAB). The shape transformation is thoroughly investigated by experimental characterization and density functional theory calculations, revealing the surface selective etching effect of DDAB. Among the {002}, {220}, and {112} facets in dodecahedron CsPbBr3 nanocrystals, DDAB has the highest binding energy with the (220) facet, which accounts for surface selectivity and shape transformation. PeLEDs based on DDAB-capped CsPbBr3 nanocrystals exhibit average and maximum external quantum efficiencies (EQE) of 14.6 and 18.5%, respectively. Therefore, the ligand exchange using DDAB is an effective strategy for the production of high-quality perovskite nanocrystals for optoelectronic applications.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Qiliang Zhu,Wenxuan Huang,Jianhua Shen,Haibo Jiang,Yihua Zhu,Chunzhong Li
Metal halide perovskite nanocrystals have garnered significant attention in the realm of photocatalytic CO 2 reduction in recent years owing to their remarkable reducing properties and high selectivity. However, the issue of low photocatalytic activity due to severe carrier recombination phenomena in perovskite has posed a significant challenge. To address this, a one-pot in-situ preparation strategy was employed to create a BiOBr/Bi-doped perovskite nanocrystal S-scheme heterojunction, resulting in a significant improvement in the CO 2 photoreduction performance. The heterojunction material exhibited a CO yield of 151.56 μmolg -1 h −1 , with a selectivity for CO of 93.6 %. The molar ratio of the components was modulated using an in-situ water aging strategy, yielding a photocatalyst performance that exceeded that of pure BiOBr. The synthesis strategy of one-step in-situ preparation of heterojunctions overcomes the problem of insufficient bonding caused by two-step methods. And various characterizations and DFT calculations strongly support the S-scheme mechanism of the photocatalyst. The active site effectively reduces the energy barrier for the transition from *COOH to *CO intermediate, thereby significantly improving photocatalytic activity.
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