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Braunschweig H, Ewing WC, Ghosh S, Kramer T, Mattock JD, Östreicher S, Vargas A, Werner C. Trimetallaborides as starting points for the syntheses of large metal-rich molecular borides and clusters. Chem Sci 2016; 7:109-116. [PMID: 29861971 PMCID: PMC5950574 DOI: 10.1039/c5sc03206g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 10/19/2015] [Indexed: 11/21/2022] Open
Abstract
Treatment of an anionic dimanganaborylene complex ([{Cp(CO)2Mn}2B]-) with coinage metal cations stabilized by a very weakly coordinating Lewis base (SMe2) led to the coordination of the incoming metal and subsequent displacement of dimethylsulfide in the formation of hexametalladiborides featuring planar four-membered M2B2 cores (M = Cu, Au) comparable to transition metal clusters constructed around four-membered rings composed solely of coinage metals. The analogies between compounds consisting of B2M2 units and M4 (M = Cu, Au) units speak to the often overlooked metalloid nature of boron. Treatment of one of these compounds (M = Cu) with a Lewis-basic metal fragment (Pt(PCy3)2) led to the formation of a tetrametallaboride featuring two manganese, one copper and one platinum atom, all bound to boron in a geometry not yet seen for this kind of compound. Computational examination suggests that this geometry is the result of d10-d10 dispersion interactions between the copper and platinum fragments.
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Affiliation(s)
- Holger Braunschweig
- Institut für Anorganische Chemie , Julius-Maximilians-Universität Würzburg , Am Hubland , 97074 Würzburg , Germany .
| | - William C Ewing
- Institut für Anorganische Chemie , Julius-Maximilians-Universität Würzburg , Am Hubland , 97074 Würzburg , Germany .
| | - Sundargopal Ghosh
- Department of Chemistry , Indian Institute of Technology Madras , Chennai 600 036 , India
| | - Thomas Kramer
- Institut für Anorganische Chemie , Julius-Maximilians-Universität Würzburg , Am Hubland , 97074 Würzburg , Germany .
| | - James D Mattock
- Department of Chemistry , School of Life Sciences , University of Sussex , Brighton BN1 9QJ , Sussex , UK
| | - Sebastian Östreicher
- Institut für Anorganische Chemie , Julius-Maximilians-Universität Würzburg , Am Hubland , 97074 Würzburg , Germany .
| | - Alfredo Vargas
- Department of Chemistry , School of Life Sciences , University of Sussex , Brighton BN1 9QJ , Sussex , UK
| | - Christine Werner
- Institut für Anorganische Chemie , Julius-Maximilians-Universität Würzburg , Am Hubland , 97074 Würzburg , Germany .
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Synthesis and Characterization of Vanadium Doped Zinc Oxide Thick Film for Chemical Sensor Application. ACTA ACUST UNITED AC 2015. [DOI: 10.1155/2015/196545] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Zinc oxide and vanadium pentoxide nanoparticles derived by chemical coprecipitation route were used to cast Zn0.96V0.04O thick film by screen printing method. The structural, morphological, optical, and electrical properties of the film were characterized by powder XRD, SEM, Raman, UV-VIS, and DC conductivity techniques. XRD pattern, SEM image, and Raman spectrum of the film confirm the single phase formation of Wurtzite structure with preferential orientation along [101] plane, minor variation in lattice parameters, and vanadium ions substitution at zinc sites. Zn0.96V0.04O pellet has been used for sensing ammonia vapor concentrations in 20–50°C temperature range which exhibits maximum responsiveness and sensitivity at 30°C. The minor variations in resistance are observed with ammonia vapor concentration. The adsorption of ammonia vapors through weak hydrogen bonding and its insertion into lattice by nitrogen lone pairs donation at vacant/defect sites in lattice caused by vanadium doping are considered to explain gas sensing mechanism.
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Xiang D, Han C, Hu Z, Lei B, Liu Y, Wang L, Hu WP, Chen W. Surface Transfer Doping-Induced, High-Performance Graphene/Silicon Schottky Junction-Based, Self-Powered Photodetector. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 11:4829-4836. [PMID: 26189341 DOI: 10.1002/smll.201501298] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Indexed: 06/04/2023]
Affiliation(s)
- Du Xiang
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, 117546, Singapore
| | - Cheng Han
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, 117546, Singapore
| | - Zehua Hu
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, 117546, Singapore
| | - Bo Lei
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, 117546, Singapore
| | - Yiyang Liu
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, 117546, Singapore
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Li Wang
- Institute for Advanced Study and Department of Physics, Nanchang University, 999 Xue Fu Da Dao, Nanchang, 330031, China
| | - Wen Ping Hu
- Department of Chemistry, School of Science, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, 300072, China
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Wei Chen
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, 117546, Singapore
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
- National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Jiang Su, 215123, China
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Zhang HD, Yu M, Zhang JC, Sheng CH, Yan X, Han WP, Liu YC, Chen S, Shen GZ, Long YZ. Fabrication and photoelectric properties of La-doped p-type ZnO nanofibers and crossed p-n homojunctions by electrospinning. NANOSCALE 2015; 7:10513-10518. [PMID: 26008851 DOI: 10.1039/c5nr02191j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
La-doped p-type ZnO nanofibers were successfully synthesized by electrospinning, followed by calcination. The microstructure and morphology of the La-doped ZnO nanofibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The field effect curve of individual nanofibers confirms that the resulting La-doped ZnO fibers are p-type semiconductors. The doping mechanism is discussed. Furthermore, crossed p-n homojunction nanofibers were also prepared based on electrospun La-doped p-type ZnO and n-type pure ZnO fibers. The current-voltage curve shows the typical rectifying characteristic of a p-n homojunction device. The turn-on voltage appears at about 2.5 V under the forward bias and the reverse current is impassable.
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Affiliation(s)
- H D Zhang
- College of Physics & Collaborative Innovation Center for Low-Dimensional Nanomaterials and Optoelectronic Devices, Qingdao University, Qingdao 266071, China.
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Ding H, Shao J, Ding Y, Liu W, Tian H, Li X. One-Dimensional Au-ZnO Heteronanostructures for Ultraviolet Light Detectors by a Two-Step Dielectrophoretic Assembly Method. ACS APPLIED MATERIALS & INTERFACES 2015; 7:12713-12718. [PMID: 26009795 DOI: 10.1021/acsami.5b01362] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
One-dimensional ZnO decorated with metal nanoparticles has received much attention in the field of ultraviolet light detection because of its high photosensitivity and fast response, while how to form effective metal-ZnO heterostructures cost efficiently is still in development. We report an efficient and well-controlled method to form Au-ZnO heterostructures by two-step dielectrophoretic assembly. First, ZnO nanowires dispersed in deionized water were assembled dielectrophoretically in a planar microelectrode system. To control the number and position of assembled ZnO nanowires, a planar triangle-shaped microelectrode pair was imposed with a high-frequency ac voltage signal in this assembly process. Then a droplet of Au nanoparticle suspension was applied to decorate the preformed ZnO nanowire by another dielectrophoretic assembly process. The near-field dielectrophoretic force induced by the existence of ZnO nanowire spanning the electrode gap attracts Au nanoparticles onto the surface of ZnO nanowires and forms effective Au-ZnO heterostructures. After the adsorption of Au nanoparticles, the performances of Au-ZnO heteronanostructures in UV detection were studied. Experimental results indicate that the ratio of the photo-to-dark current of the Au-ZnO heteronanostucture-based detector was improved significantly, and the photoresponse was accelerated considerably. This kind of enhancement in performance can be attributed to the localized Schottky junctions on the surface of ZnO nanowire which improves the surface band bending.
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Affiliation(s)
- Haitao Ding
- Micro- and Nano-manufacturing Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Jinyou Shao
- Micro- and Nano-manufacturing Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Yucheng Ding
- Micro- and Nano-manufacturing Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Weiyu Liu
- Micro- and Nano-manufacturing Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Hongmiao Tian
- Micro- and Nano-manufacturing Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Xiangming Li
- Micro- and Nano-manufacturing Research Center, State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
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Pauporté T, Lupan O, Zhang J, Tugsuz T, Ciofini I, Labat F, Viana B. Low-Temperature Preparation of Ag-Doped ZnO Nanowire Arrays, DFT Study, and Application to Light-Emitting Diode. ACS APPLIED MATERIALS & INTERFACES 2015; 7:11871-11880. [PMID: 25990263 DOI: 10.1021/acsami.5b01496] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Doping ZnO nanowires (NWs) by group IB elements is an important challenge for integrating nanostructures into functional devices with better and tuned performances. The growth of Ag-doped ZnO NWs by electrodeposition at 90 °C using a chloride bath and molecular oxygen precursor is reported. Ag acts as an electrocatalyst for the deposition and influences the nucleation and growth of the structures. The silver atomic concentration in the wires is controlled by the additive concentration in the deposition bath and a content up to 3.7 atomic % is reported. XRD analysis shows that the integration of silver enlarges the lattice parameters of ZnO. The optical measurements also show that the direct optical bandgap of ZnO is reduced by silver doping. The bandgap shift and lattice expansion are explained by first principle calculations using the density functional theory (DFT) on the silver impurity integration as an interstitial (Ag(i)) and as a substitute of zinc atom (Ag(Zn)) in the crystal lattice. They notably indicate that Ag(Zn) doping forms an impurity band because of Ag 4d and O 2p orbital interactions, shifting the Fermi level toward the valence band. At least, Ag-doped ZnO vertically aligned nanowire arrays have been epitaxially grown on GaN(001) substrate. The heterostructure has been inserted in a light emitting device. UV-blue light emission has been achieved with a low emission threshold of 5 V and a tunable red-shifted emission spectrum related to the bandgap reduction induced by silver doping of the ZnO emitter material.
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Affiliation(s)
- Thierry Pauporté
- †Institut de Recherche de Chimie-Paris, CNRS-Chimie ParisTech-PSL, UMR8247, 11 rue Pierre et Marie Curie, 75005 Paris, France
| | - Oleg Lupan
- †Institut de Recherche de Chimie-Paris, CNRS-Chimie ParisTech-PSL, UMR8247, 11 rue Pierre et Marie Curie, 75005 Paris, France
- ‡Department of Microelectronics and Biomedical Engineering, Technical University of Moldova, 168 Stefan cel Mare Boulevard, Chisinau MD-2004, Republic of Moldova
| | - Jie Zhang
- †Institut de Recherche de Chimie-Paris, CNRS-Chimie ParisTech-PSL, UMR8247, 11 rue Pierre et Marie Curie, 75005 Paris, France
| | - Tugba Tugsuz
- †Institut de Recherche de Chimie-Paris, CNRS-Chimie ParisTech-PSL, UMR8247, 11 rue Pierre et Marie Curie, 75005 Paris, France
| | - Ilaria Ciofini
- †Institut de Recherche de Chimie-Paris, CNRS-Chimie ParisTech-PSL, UMR8247, 11 rue Pierre et Marie Curie, 75005 Paris, France
| | - Frédéric Labat
- †Institut de Recherche de Chimie-Paris, CNRS-Chimie ParisTech-PSL, UMR8247, 11 rue Pierre et Marie Curie, 75005 Paris, France
| | - Bruno Viana
- †Institut de Recherche de Chimie-Paris, CNRS-Chimie ParisTech-PSL, UMR8247, 11 rue Pierre et Marie Curie, 75005 Paris, France
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Park JB, Chun YT, Lee YB, Sohn JI, Hong WK. Defect-mediated modulation of optical properties in vertically aligned ZnO nanowires via substrate-assisted Ga incorporation. NANOTECHNOLOGY 2015; 26:145202. [PMID: 25771907 DOI: 10.1088/0957-4484/26/14/145202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report the defect-mediated modulation of optical properties in vertically aligned ZnO nanowires via a substrate-assisted Ga incorporation method. We find that Ga atoms were incorporated into a ZnO lattice via the diffusion of liquid Ga droplets from a GaAs substrate in which as-grown ZnO nanowires were placed face down on the GaAs substrate and annealed at 650 °C. Based on structural and compositional characterization, it was confirmed that the substrate-assisted incorporation of Ga can induce a high defect density in vertically aligned ZnO nanowires grown on a Si substrate. In addition, distinct differences in optical properties between as-grown and Ga-incorporated ZnO nanowires were found and discussed in terms of defect-mediated modifications of energy band states, which were associated with the generation and recombination of photoexcited carriers. Furthermore, it was clearly observed that for Ga-incorporated ZnO nanowires, the photocurrent rise and decay processes were slower and the photocurrents under UV illumination were significantly higher compared with as-grown nanowires.
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Affiliation(s)
- Jong Bae Park
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK
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58
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Šutka A, Timusk M, Döbelin N, Pärna R, Visnapuu M, Joost U, Käämbre T, Kisand V, Saal K, Knite M. A straightforward and “green” solvothermal synthesis of Al doped zinc oxide plasmonic nanocrystals and piezoresistive elastomer nanocomposite. RSC Adv 2015. [DOI: 10.1039/c5ra11910c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Ethanol solvothermal method derives plasmonic Al doped ZnO nanocrystals suitable for advanced applications.
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Affiliation(s)
- Andris Šutka
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
- Institute of Silicate Materials
| | - Martin Timusk
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
- Institute of Technical Physics
| | | | - Rainer Pärna
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
| | - Meeri Visnapuu
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
| | - Urmas Joost
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
| | - Tanel Käämbre
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
| | - Vambola Kisand
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
| | - Kristjan Saal
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
| | - Maris Knite
- Institute of Technical Physics
- Riga Technical University
- Riga LV-1048
- Latvia
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59
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Pal S, Maiti S, Maiti UN, Chattopadhyay KK. Spontaneous hyper-branching in ZnO nanostructures: morphology dependent electron emission and light detection. RSC Adv 2015. [DOI: 10.1039/c5ra12838b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The structure and intrinsic defect-induced electron field emission and photodetection are monitored in ZnO nanoforms with assorted morphology prepared in ambient conditions via a facile wet chemical approach.
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Affiliation(s)
- Shreyasi Pal
- Thin Films and Nanoscience Laboratory
- Department of Physics
- Jadavpur University
- Kolkata 700032
- India
| | - Soumen Maiti
- Thin Films and Nanoscience Laboratory
- Department of Physics
- Jadavpur University
- Kolkata 700032
- India
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