1
|
Mazzola F, Hassani H, Amoroso D, Chaluvadi SK, Fujii J, Polewczyk V, Rajak P, Koegler M, Ciancio R, Partoens B, Rossi G, Vobornik I, Ghosez P, Orgiani P. Unveiling the Electronic Structure of Pseudotetragonal WO 3 Thin Films. J Phys Chem Lett 2023; 14:7208-7214. [PMID: 37551605 PMCID: PMC10440808 DOI: 10.1021/acs.jpclett.3c01546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 07/26/2023] [Indexed: 08/09/2023]
Abstract
WO3 is a 5d compound that undergoes several structural transitions in its bulk form. Its versatility is well-documented, with a wide range of applications, such as flexopiezoelectricity, electrochromism, gating-induced phase transitions, and its ability to improve the performance of Li-based batteries. The synthesis of WO3 thin films holds promise in stabilizing electronic phases for practical applications. However, despite its potential, the electronic structure of this material remains experimentally unexplored. Furthermore, its thermal instability limits its use in certain technological devices. Here, we employ tensile strain to stabilize WO3 thin films, which we call the pseudotetragonal phase, and investigate its electronic structure using a combination of photoelectron spectroscopy and density functional theory calculations. This study reveals the Fermiology of the system, notably identifying significant energy splittings between different orbital manifolds arising from atomic distortions. These splittings, along with the system's thermal stability, offer a potential avenue for controlling inter- and intraband scattering for electronic applications.
Collapse
Affiliation(s)
- F. Mazzola
- Department
of Molecular Sciences and Nanosystems, Ca’
Foscari University of Venice, 30172 Venice, Italy
- Istituto
Officina dei Materiali (IOM)-CNR, Area Science Park, 34149 Trieste, Italy
| | - H. Hassani
- Theoretical
Materials Physics, Q-MAT, CESAM, Université
de Liège, B-4000 Liège, Belgium
- Department
of Physics, University of Antwerp, 2020 Antwerp, Belgium
| | - D. Amoroso
- Theoretical
Materials Physics, Q-MAT, CESAM, Université
de Liège, B-4000 Liège, Belgium
| | - S. K. Chaluvadi
- Istituto
Officina dei Materiali (IOM)-CNR, Area Science Park, 34149 Trieste, Italy
| | - J. Fujii
- Istituto
Officina dei Materiali (IOM)-CNR, Area Science Park, 34149 Trieste, Italy
| | - V. Polewczyk
- Istituto
Officina dei Materiali (IOM)-CNR, Area Science Park, 34149 Trieste, Italy
| | - P. Rajak
- Istituto
Officina dei Materiali (IOM)-CNR, Area Science Park, 34149 Trieste, Italy
| | - Max Koegler
- Istituto
Officina dei Materiali (IOM)-CNR, Area Science Park, 34149 Trieste, Italy
| | - R. Ciancio
- Area
Science Park, Padriciano
99, 34149 Trieste, Italy
| | - B. Partoens
- Department
of Physics, University of Antwerp, 2020 Antwerp, Belgium
| | - G. Rossi
- Istituto
Officina dei Materiali (IOM)-CNR, Area Science Park, 34149 Trieste, Italy
- University
of Milano, I-20133 Milano, Italy
| | - I. Vobornik
- Istituto
Officina dei Materiali (IOM)-CNR, Area Science Park, 34149 Trieste, Italy
| | - P. Ghosez
- Theoretical
Materials Physics, Q-MAT, CESAM, Université
de Liège, B-4000 Liège, Belgium
| | - P. Orgiani
- Istituto
Officina dei Materiali (IOM)-CNR, Area Science Park, 34149 Trieste, Italy
| |
Collapse
|
2
|
Merazka S, Kars M, Roisnel T, Sidoumou M. Experimental and theoretical study of novel germanium tungstates compounds GexW1-xO3 (x ∼ 1/4, 1/2) and Ge1-xWO4 (x ∼ 0.2). J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2023.135486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
|
3
|
Chen X, van Huis MA. Formation Pathways of Lath-Shaped WO 3 Nanosheets and Elemental W Nanoparticles from Heating of WO 3 Nanocrystals Studied via In Situ TEM. MATERIALS (BASEL, SWITZERLAND) 2023; 16:1291. [PMID: 36770297 PMCID: PMC9920553 DOI: 10.3390/ma16031291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 01/28/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
WO3 is a versatile material occurring in many polymorphs, and is used in nanostructured form in many applications, including photocatalysis, gas sensing, and energy storage. We investigated the thermal evolution of cubic-phase nanocrystals with a size range of 5-25 nm by means of in situ heating in the transmission electron microscope (TEM), and found distinct pathways for the formation of either 2D WO3 nanosheets or elemental W nanoparticles, depending on the initial concentration of deposited WO3 nanoparticles. These pristine particles were stable up to 600 °C, after which coalescence and fusion of the nanocrystals were observed. Typically, the nanocrystals transformed into faceted nanocrystals of elemental body-centered-cubic W after annealing to 900 °C. However, in areas where the concentration of dropcast WO3 nanoparticles was high, at a temperature of 900 °C, considerably larger lath-shaped nanosheets (extending for hundreds of nanometers in length and up to 100 nm in width) were formed that are concluded to be in monoclinic WO3 or WO2.7 phases. These lath-shaped 2D particles, which often curled up from their sides into folded 2D nanosheets, are most likely formed from the smaller nanoparticles through a solid-vapor-solid growth mechanism. The findings of the in situ experiments were confirmed by ex situ experiments performed in a high-vacuum chamber.
Collapse
Affiliation(s)
- Xiaodan Chen
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
- Electron Microscopy Center, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Marijn A. van Huis
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
- Electron Microscopy Center, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| |
Collapse
|
4
|
Surnev S, Netzer FP. Tungsten and molybdenum oxide nanostructures: two-dimensional layers and nanoclusters. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:233001. [PMID: 35045403 DOI: 10.1088/1361-648x/ac4ceb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 01/19/2022] [Indexed: 06/14/2023]
Abstract
W- and Mo-oxides form an interesting class of materials, featuring structural complexities, stoichiometric flexibility, and versatile physical and chemical properties that render them attractive for many applications in diverse fields of nanotechnologies. In nanostructured form, novel properties and functionalities emerge as a result of quantum size and confinement effects. In this topical review, W- and Mo-oxide nanosystems are examined with particular emphasis on two-dimensional (2D) layers and small molecular-type clusters. We focus on the epitaxial growth of 2D layers on metal single crystal surfaces and investigate their novel geometries and structures by a surface science approach. The coupling between the oxide overlayer and the metal substrate surface is a decisive element in the formation of the oxide structures and interfacial strain and charge transfer are shown to determine the lowest energy structures. Atomic structure models as determined by density functional theory (DFT) simulations are reported and discussed for various interface situations, with strong and weak coupling. Free-standing (quasi-)2D oxide layers, so-called oxide nanosheets, are attracting a growing interest recently in the applied research community because of their easy synthesis via wet-chemical routes. Although they consist typically of several atomic layers thick-not always homogeneous-platelet systems, their quasi-2D character induces a number of features that make them attractive for optoelectronic, sensor or biotechnological device applications. A brief account of recently published preparation procedures of W- and Mo-oxide nanosheets and some prototypical examples of proof of concept applications are reported here. (MO3)3(M = W, Mo) clusters can be generated in the gas phase in nearly monodisperse form by a simple vacuum sublimation technique. These clusters, interesting molecular-type structures by their own account, can be deposited on a solid surface in a controlled way and be condensed into 2D W- and Mo-oxide layers; solid-state chemical reactions with pre-deposited surface oxide layers to form 2D ternary oxide compounds (tungstates, molybdates) have also been reported. The clusters have been proposed as model systems for molecular studies of reactive centres in catalytic reactions. Studies of the catalysis of (MO3)3clusters in unsupported and supported forms, using the conversion of alcohols as model reactions, are discussed. Finally, we close with a brief outlook of future perspectives.
Collapse
Affiliation(s)
- Svetlozar Surnev
- Surface and Interface Physics, Institute of Physics, Karl-Franzens University Graz, A-8010 GRAZ, Austria
| | - Falko P Netzer
- Surface and Interface Physics, Institute of Physics, Karl-Franzens University Graz, A-8010 GRAZ, Austria
| |
Collapse
|
5
|
Li B, Li L, Ren H, Lu Y, Peng F, Chen Y, Hu C, Zhang G, Zou C. Photoassisted Electron-Ion Synergic Doping Induced Phase Transition of n-VO 2/p-GaN Thin-Film Heterojunction. ACS APPLIED MATERIALS & INTERFACES 2021; 13:43562-43572. [PMID: 34468117 DOI: 10.1021/acsami.1c10401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
As a typical correlated metal oxide, vanadium dioxide (VO2) shows specific metal-insulator transition (MIT) properties and demonstrates great potential applications in ultrafast optoelectronic switch, resistive memory, and neuromorphic devices. Effective control of the MIT process is essential for improving the device performance. In the current study, we have first proposed a photoassisted ion-doping method to modulate the phase transition of the VO2 layer based on the photovoltaic effect and electron-ion synergic doping in acid solution. Experimental results show that, for the prepared n-VO2/p-GaN nanojunction, this photoassisted strategy can effectively dope the n-VO2 layer by H+, Al3+, or Mg2+ ions under light radiation and trigger consecutive insulator-metal-insulator transitions. If combined with standard lithography or electron beam etching processes, selective doping with nanoscale size area can also be achieved. This photoassisted doping method not only shows a facile route for MIT modulation via a doping route under ambient conditions but also supplies some clues for photosensitive detection in the future.
Collapse
Affiliation(s)
- Bowen Li
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China
| | - Liang Li
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China
| | - Hui Ren
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China
| | - Yuan Lu
- State Key Laboratory of Pulsed Power Laser Technology, NUDT, Hefei 230037, P. R. China
- Infrared and Low Temperature Plasma Key Laboratory of Anhui Province, NUDT, Hefei 230037, P. R. China
| | - Fangfang Peng
- Center for Micro- and Nanoscale Research and Fabrication, University of Science and Technology of China, Hefei 230029, P. R. China
| | - Yuliang Chen
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China
| | - Changlong Hu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China
| | - Guobin Zhang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China
- Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei 230029, P. R. China
| | - Chongwen Zou
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China
| |
Collapse
|
6
|
Barreto TR, Gorla FA, Ferreira MDP, Duarte PHA, Ribeiro ES, Afonso JC, Tarley CRT. Synthesis and Characterization of a Silica/Tungsten(VI) Oxide and Its Performance for the On-Line Solid-Phase Extraction (SPE) of Nickel Ions from Aqueous Media with Determination by Flame Atomic Absorption Spectrometry (FAAS). ANAL LETT 2021. [DOI: 10.1080/00032719.2020.1793997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Túlio Rolim Barreto
- Department of Chemistry, State University of Londrina (UEL), Londrina, Brazil
| | - Felipe Augusto Gorla
- Department of Chemistry, State University of Londrina (UEL), Londrina, Brazil
- Campus Assis Chateaubriand, Federal Institute of Parana (IFPR), Assis Chateaubriand, Brazil
| | | | | | - Emerson Schwingel Ribeiro
- Institute of Chemistry, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro (RJ), Brazil
- National Institute for Alternative Technologies of Detection, Toxicological Evaluation and Removal of Micropollutants and Radioactives (INCT-DATREM), Institute of Chemistry, Paulista State University – Júlio de Mesquita Filho (UNESP), Araraquara (SP), Brazil
| | - Júlio Carlos Afonso
- Institute of Chemistry, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro (RJ), Brazil
| | - César Ricardo Teixeira Tarley
- Department of Chemistry, State University of Londrina (UEL), Londrina, Brazil
- National Institute of Science and Technology in Bioanalysis (INCTBio), Department of Chemistry, Institute of Chemistry, State University of Campinas (UNICAMP), Campinas, Brazil
| |
Collapse
|
7
|
Yao X, Klyukin K, Lu W, Onen M, Ryu S, Kim D, Emond N, Waluyo I, Hunt A, Del Alamo JA, Li J, Yildiz B. Protonic solid-state electrochemical synapse for physical neural networks. Nat Commun 2020; 11:3134. [PMID: 32561717 PMCID: PMC7371700 DOI: 10.1038/s41467-020-16866-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 05/15/2020] [Indexed: 11/24/2022] Open
Abstract
Physical neural networks made of analog resistive switching processors are promising platforms for analog computing. State-of-the-art resistive switches rely on either conductive filament formation or phase change. These processes suffer from poor reproducibility or high energy consumption, respectively. Herein, we demonstrate the behavior of an alternative synapse design that relies on a deterministic charge-controlled mechanism, modulated electrochemically in solid-state. The device operates by shuffling the smallest cation, the proton, in a three-terminal configuration. It has a channel of active material, WO3. A solid proton reservoir layer, PdHx, also serves as the gate terminal. A proton conducting solid electrolyte separates the channel and the reservoir. By protonation/deprotonation, we modulate the electronic conductivity of the channel over seven orders of magnitude, obtaining a continuum of resistance states. Proton intercalation increases the electronic conductivity of WO3 by increasing both the carrier density and mobility. This switching mechanism offers low energy dissipation, good reversibility, and high symmetry in programming.
Collapse
Affiliation(s)
- Xiahui Yao
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Konstantin Klyukin
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Wenjie Lu
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Murat Onen
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Seungchan Ryu
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Dongha Kim
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Nicolas Emond
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Iradwikanari Waluyo
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Adrian Hunt
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Jesús A Del Alamo
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
| | - Ju Li
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
| | - Bilge Yildiz
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
| |
Collapse
|
8
|
Lin H, Long X, An Y, Yang S. In situ growth of Fe2WO6 on WO3 nanosheets to fabricate heterojunction arrays for boosting solar water splitting. J Chem Phys 2020; 152:214704. [DOI: 10.1063/5.0008227] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- He Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
- Guangdong Key Laboratory of Nano-Micro Materials Research, School of Chemical Biology and Biotechnology, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Xia Long
- Guangdong Key Laboratory of Nano-Micro Materials Research, School of Chemical Biology and Biotechnology, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Yiming An
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Shihe Yang
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
- Guangdong Key Laboratory of Nano-Micro Materials Research, School of Chemical Biology and Biotechnology, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| |
Collapse
|
9
|
Zhu F, Ma C, Gu L, Chen G, Zhang J, Cong S, Zhao Z, Zhang X. Off-centered-symmetry-based band structure modulation of hexagonal WO 3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:355501. [PMID: 31108470 DOI: 10.1088/1361-648x/ab2327] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The accurate band gap of 2.24 eV for hexagonal WO3 is obtained by adopting the revised Heyd-Scuseria-Ernzerhof screened hybrid functional. The large band gap is a result of the off-centered symmetry where the W atom forms two short and two long bonds with four neighboring in-plane O atoms. By adding/removing electrons into/from the crystal, the effect of charge doping is investigated. With introducing electrons, the off-centered symmetry gets weakened with a slight narrowing in band gap. However, the doping lifts the Fermi level into the conduction band, inducing an increase in transition energy for electrons. Similarly, the hole doping also results in a remarkable increase in the transition energy. Such band structure modulation can be used in high efficient photoabsorption, photocatalysis and surface-enhanced Raman spectroscopy.
Collapse
Affiliation(s)
- Feng Zhu
- Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Mathematics and Physics, Suzhou University of Science and Technology, Suzhou 215009, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|