Abstract
The field-emission properties of molybdenum oxide nanowires grown on a silicon substrate and its emission performance in various vacuum gaps are reported in this article. A new kind of molybdenum oxides named nanowires with nanoscale protrusions on their surfaces were grown by thermal vapor deposition with a length of ~1 μm and an average diameter of ~50 nm. The morphology, structure, composition and chemical states of the prepared nanostructures were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). According to XRD, XPS, and TEM analyses, the synthesized samples were composed of MoO2 nanowires formed over a thin layer of crystalline Mo4O11. TEM observation revealed that these nanowires have some nanoscale protrusion on their surface. These nanoprotrusions resulted in enhancement of field-emission properties of nanowires comprising nanoprotrusions. The turn-on emission field and the enhancement factor of this type of nanostructures were measured 0.2 V/μm and 42991 at the vacuum gap of 300 μm, respectively. These excellent emission properties are attributed to the special structure of the nanowires that have potential for utilizing in vacuum nanoelectronic and microelectronic applications.
References
Al-Kandari S, Al-Kandari H, Al-Kharafi F, Katrib A (2008) The catalytic reactions of n-pentane and 1-pentene on different molybdenum oxides and metal surfaces. Appl Catal A 341(1–2):160–167
Azimirad R, Khademi A, Akhavan O, Moshfegh AZ (2009) Growth of Na0.3WO3 nanorods for the field emission application. J Phys D 42:205405.1–205405.6
Baek Y, Yong K (2007) Controlled growth and characterization of tungsten oxide nanowires using thermal evaporation of WO3 powder. J Phys Chem C 111:1213–1218
Bhosle V, Tiwari A, Narayan J (2005) Epitaxial growth and properties of MoO x (2 < x<2.75) films. J Appl Phys 97:083539-1–083539-6
Brox B, Olefjord I (1988) ESCA Studies of MoO2 and MoO3. Surf Interface Anal 13:3–6
Chang M-T, Chou L-J, Chueh Y-L, Lee Y-C, Hsieh C-H, Chen C-D, Lan Y-W, Chen L-J (2007) Nitrogen-doped tungsten oxide nanowires: low-temperature synthesis on Si, and electrical, optical, and field-emission properties. Small 3(4):658–664
Cho C-P, Perng T-P (2007) Field emission of Alq3 nanoprotrusions. Nanotechnology 18:125202 (5 pp)
Choi J–G, Thompson LT (1996) XPS study of as-prepared and reduced molybdenum oxides. Appl Surf Sci 93(2):143–149
Connolly T, Smith RC, Hernandez Y, Gun’ko Y, Coleman JN, Carey JD (2009) Carbon-nanotube-polymer nanocomposites for field-emission cathodes. Small 5(7):826–831
Hu B, Mai L, Chen W, Yang F (2009) From MoO3 nanobelts to MoO2 nanorods: structure transformation and electrical transport. ACS Nano 3(2):478–482
Huang K, Pan Q, Yang F, Ni Sh, He D (2007) Growth and field emission of tungsten oxide nanotip arrays on ITO glass substrate. Appl Surf Sci 253:8923–8927
Huang K, Pan Q, Yang F, Ni S, He D (2008) The catalyst-free synthesis of large-area tungsten oxide nanowire arrays on ITO substrate and field emission properties. Mater Res Bull 43:919–925
Khademi A, Azimirad R, Zavarian AA, Moshfegh AZ (2009) Growth and field emission study of molybdenum oxide nanostars. J Phys Chem C 113:19298–19304
Kim G–T, Park T–K, Chung H, Kim Y–T, Kwon M–H, Choi J–G (1999) Growth and characterization of chloronitroaniline crystals for optical parametric oscillators: I. XPS study of Mo-based compounds. Appl Surf Sci 152(1–2):35–43
Knizhnik AA, Iskandarova IM, Bagaturyants AA, Potapkin BV, Fonseca LRC (2005) Impact of oxygen on the work functions of Mo in vacuum and on ZrO2. J Appl Phys 97:064911-1–064911-6
Late DJ, Misra P, Singh BN, Kukreja LM, Joag DS, More MA (2009) Enhanced field emission from pulsed laser deposited nanocrystalline ZnO thin films on Re and W. Appl Phys A 95(2):613–620
Late DJ, Kashid RV, Rout CS, More MA, Joag DS (2010) Low threshold field electron emission from solvothermally synthesized WO2.72 nanowires. Appl Phys A 98(4):751–756
Lee K-H, Shin C-D, Chen I-G, Li B-J (2007) The effect of nanoscale protrusions on field-emission properties for GaN nanowires. J Electrochem Soc 154(10):K87–K91
Li YB, Bando Y, Golberg D, Kurashima K (2002) Field emission from MoO3 nanobelts. Appl Phys Lett 81(26):5048–5050
Li M-K, Wang D-Z, Ding Y-W, Guo X-Y, Ding S, Jin H (2007) Morphology and field emission from ZnO nanowire arrays synthesized at different temperature. Mater Sci Eng A 452–453:417–421
Li L, Xu X, Chew H, Huang X, Dou X, Pan S, Li G, Zhang L (2008) Direct growth of Al nanowire arrays: thermal expansion and field emission properties. J Phys Chem C 112:5328–5332
Liang Y, Tracy C, Weisbrod E, Fejes P, Theodore ND (2006) Effect of SiO2 incorporation on stability and work function of conducting MoO2. Appl Phys Lett 88:081901-1–081901-3
Liu J, Zhao Y, Zhang Z (2003) Low-temperature synthesis of large-scale arrays of aligned tungsten oxide nanorods. J Phys Condens Matter 15:L453–L461
Liu J, Zhang Z, Pan C, Zhao Y, Su X, Zhou Y, Yu D (2004) Enhanced field emission properties of MoO2 nanorods with controllable shape and orientation. Mater Lett 58:3812–3815
Liu BD, Bando Y, Tang CC, Xu FF, Golberg D (2005) Excellent field-emission properties of P-doped GaN nanowires. J Phys Chem B 109:21521–21524
Liu X–X, Bian L–J, Zhang L, Zhang L–J (2007) Composite films of polyaniline and molybdenum oxide formed by electrocodeposition in aqueous media. J Solid State Electrochem 11(9):1279–1286
Luo L, Yu K, Zhu Z, Zhang Y, Ma H, Xue C, Yang Y, Chen S (2004) Field emission from GaN nanobelts with herringbone morphology. Mater Lett 58:2893–2896
Mendes FMT, Weibel DE, Blum R–P, Middeke J, Hafemeister M, Niehus H, Achete CA (2008) Preparation and characterization of well-ordered MoOx films on Cu3Au(1 0 0)–oxygen substrate (CAOS). Catal Today 133:187–191
Patil RS, Uplane MD, Patil PS (2006) Structural and optical properties of electrodeposited molybdenum oxide thin films. Appl Surf Sci 252(23):8050–8056
Seelaboyina R, Huang J, Park J, Kang DH, Choi WB (2006) Multistage field enhancement of tungsten oxide nanowires and its field emission in various vacuum conditions. Nanotechnology 17:4840–4844
Wang JX, Liu DF, Yan XQ, Yuan HJ, Ci LJ, Zhou ZP, Gao Y, Song L, Liu LF, Zhou WY, Wang G, Xie SS (2004) Growth of SnO2 nanowires with uniform branched structures. Solid State Commun 130:89–94
Wang J, Sun XW, Xie S, Zhou W, Yang Y (2008) Single-crystal and twinned Zn2SnO4 nanowires with axial periodical structures. Cryst Growth Des 8(2):707–710
Wei G, Qin W, Zhang D, Wang G, Kim R, Zheng K, Wang L (2009) Synthesis and field emission of MoO3 nanoflowers by a microwave hydrothermal route. J Alloys Comp 481:417–421
Wu Z-S, Pei S, Ren W, Tang D, Gao L, Liu B, Li F, Liu C, Cheng H-M (2009) Field emission of single-layer graphene films prepared by electrophoretic deposition. Adv Mat 21:1756–1760
Yao I-C, Lin P, Tseng T-Y (2009) Nanotip fabrication of zinc oxide nanorods and their enhanced field emission properties. Nanotechnology 20:125202 (5 pp)
Yuan ZJ, Gang LY, Lin SS, Guo WY, Hong WT (2008) Low-field electron emission from pinaster-like MoO2 nanoarrays as two-stage emitters. Chin Phys B 17(11):4333–4336
Zhang Q, Zhang Y, Yu K, Zhu Z (2008) Photoluminescence and field-emission characteristics of ZnO nanowires synthesized by two-step method. Vacuum 82(1):30–34
Zheng Z, Yan B, Zhang J, You Y, Lim CT, Shen Z, Yu T (2008) Potassium tungsten bronze nanowires: polarized micro-raman scattering of individual nanowires and electron field emission from nanowire films. Adv Mat 20(2):352–356
Zhong DY, Zhang GY, Liu S, Sakurai T, Wang EG (2002) Universal field-emission model for carbon nanotubes on a metal tip. Appl Phys Lett 80:506-1–506-3
Zhou J, Xu NS, Deng SZ, Chen J, She JC, Wang ZL (2003a) Large-area nanowire arrays of molybdenum and molybdenum oxides: synthesis and field emission properties. Adv Mater 15(21):1835–1840
Zhou J, Deng SZ, Xu NS, Chen J, She JC (2003b) Synthesis and field-emission properties of aligned MoO3 nanowires. Appl Phys Lett 83(13):2653–2655
Zhou J, Gong L, Deng SZ, Chen J, She JC, Xu NS, Yang R, Wang ZL (2005) Growth and field-emission property of tungsten oxide nanotip arrays. Appl Phys Lett 87:223108-1–223108-3
Zhou J, Deng S, Gong L, Ding Y, Chen J, Huang J, Chen J, Xu N, Wang ZL (2006) Growth of large-area aligned molybdenum nanowires by high temperature chemical vapor deposition: synthesis, growth mechanism, and device application. J Phys Chem B 110:10296–10302
Acknowledgments
Authors would like to thank Research and Technology Council of the Sharif University of Technology for the supporting the project. In addition, useful discussion with Dr. O. Akhavan and assistant of Mr. Rafiee for XPS measurements are greatly acknowledged.
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Khademi, A., Azimirad, R., Nien, YT. et al. Field-emission enhancement of molybdenum oxide nanowires with nanoprotrusions. J Nanopart Res 13, 115–125 (2011). https://doi.org/10.1007/s11051-010-0009-0
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DOI: https://doi.org/10.1007/s11051-010-0009-0