Substrate temperature effects on the structural, compositional, and electrical properties of VO2 thin films deposited by pulsed laser deposition

作者：Umar Z A; Ahmed N; Ahmed R; Arshad M; Anwar Ul Haq M; Hussain T; Baig M A

来源：Surface and Interface Analysis, 2018, 50(3): 297-303.

DOI：10.1002/sia.6368

<jats:p>The vanadium dioxide (VO<jats:sub>2</jats:sub>) thin films were deposited on silicon (100) substrate using the pulsed laser deposition technique. The thin films were deposited at different substrate temperatures (500°C, 600°C, 700°C, and 800°C) while keeping all the other parameters constant. X‐ray diffraction confirmed the crystalline VO<jats:sub>2</jats:sub> (B) and VO<jats:sub>2</jats:sub> (M) phase formation at different substrate temperatures. X‐ray photoelectron spectroscopy analysis showed the presence of V<jats:sup>4+</jats:sup> and V<jats:sup>5+</jats:sup> charge states in all the deposited thin films which confirms that the deposited films mainly consist of VO<jats:sub>2</jats:sub> and V<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub>. An increase in the VO<jats:sub>2</jats:sub>/V<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> ratio has been observed in the films deposited at higher substrate temperatures (700°C and 800°C). Scanning electron microscope micrographs revealed different surface morphologies of the thin films deposited at different substrate temperatures. The electrical properties showed the sharp semiconductor to metal transition behavior with approximately 2 orders of magnitude for the VO<jats:sub>2</jats:sub> thin film deposited at 800°C. The transition temperature for heating and cooling cycles as low as 46.2°C and 42°C, respectively, has been observed which is related to the smaller difference in the interplanar spacing between the as‐deposited thin film and the standard rutile VO<jats:sub>2</jats:sub> as well as to the lattice strain of approximately −1.2%.</jats:p>

• 出版日期2018-3