Tuning the Metal-Insulator Transition Properties of VO2 Thin Films with the Synergetic Combination of Oxygen Vacancies, Strain Engineering, and Tungsten Doping

Mohamed A Basyooni; Mawaheb Al-Dossari; Shrouk E Zaki; Yasin Ramazan Eker; Mucahit Yilmaz; Mohamed Shaban

doi:10.3390/nano12091470

Tuning the Metal-Insulator Transition Properties of VO₂ Thin Films with the Synergetic Combination of Oxygen Vacancies, Strain Engineering, and Tungsten Doping

Nanomaterials (Basel). 2022 Apr 26;12(9):1470. doi: 10.3390/nano12091470.

Authors

Mohamed A Basyooni^{1

2

3}, Mawaheb Al-Dossari^{4

5}, Shrouk E Zaki^{1

3}, Yasin Ramazan Eker^{3

6}, Mucahit Yilmaz², Mohamed Shaban^{7

8}

Affiliations

¹ Department of Nanotechnology and Advanced Materials, Graduate School of Applied and Natural Science, Selçuk University, Konya 42030, Turkey.
² Department of Nanoscience and Nanoengineering, Institute of Science and Technology, University of Necmettin Erbakan, Konya 42060, Turkey.
³ Science and Technology Research and Application Center (BITAM), University of Necmettin Erbakan, Konya 42060, Turkey.
⁴ Research Center for Advanced Materials Science (RCAMS), King Khalid University, Abha 61413, Saudi Arabia.
⁵ Department of Physics, Dhahran Aljanoub, King Khalid University, Abha 61421, Saudi Arabia.
⁶ Department of Metallurgy and Material Engineering, Faculty of Engineering and Architecture, Necmettin Erbakan University, Konya 42060, Turkey.
⁷ Department of Physics, Faculty of Science, Islamic University of Madinah, AlMadinah Almonawara 42351, Saudi Arabia.
⁸ Nanophotonics and Applications Laboratory, Physics Department, Faculty of Science, Beni-Suef University, Beni-Suef 62514, Egypt.

Abstract

Vanadium oxide (VO₂) is considered a Peierls-Mott insulator with a metal-insulator transition (MIT) at T_c = 68° C. The tuning of MIT parameters is a crucial point to use VO₂ within thermoelectric, electrochromic, or thermochromic applications. In this study, the effect of oxygen deficiencies, strain engineering, and metal tungsten doping are combined to tune the MIT with a low phase transition of 20 °C in the air without capsulation. Narrow hysteresis phase transition devices based on multilayer VO₂, WO₃, Mo_0.2W_0.8O_3, and/or MoO₃ oxide thin films deposited through a high vacuum sputtering are investigated. The deposited films are structurally, chemically, electrically, and optically characterized. Different conductivity behaviour was observed, with the highest value towards VO_1.75/WO_2.94 and the lowest VO_1.75 on FTO glass. VO_1.75/WO_2.94 showed a narrow hysteresis curve with a single-phase transition. Thanks to the role of oxygen vacancies, the MIT temperature decreased to 35 °C, while the lowest value (T_c = 20 °C) was reached with Mo_0.2W_0.8O₃/VO₂/MoO₃ structure. In this former sample, Mo_0.2W_0.8O₃ was used for the first time as an anti-reflective and anti-oxidative layer. The results showed that the MoO₃ bottom layer is more suitable than WO₃ to enhance the electrical properties of VO₂ thin films. This work is applied to fast phase transition devices.

Keywords: metal–insulator transition; phase transition device; thermochromic; thin films; vanadium oxide.

Abstract

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