Tungsten-doped vanadium dioxide thin film synthesis by alternate layer-by-layer growth and post-deposition annealing

摘要

Intrinsic vanadium dioxide (VO2) encounters a metal-insulator transition (MIT) sharply at similar to 67 degrees C. Incorporating W6+ into VO2 enables lowering the MIT temperature effectually. Here we have developed a novel two-step synthesis process of high-quality W-doped VO2 thin films along with a delicate doping control: deposition of nanoscale alternately-layered precursor films composed of V and V-W layers by successive sputtering and subsequent annealing. The produced films have been characterized comprehensively to understand the effects of W-doping and process parameters into MIT functionality and structural properties in detail. With W-doping, the change rate of the MIT temperature was determined as similar to -14.5 degrees C/at%W while the resistance change across MIT decreases considerably. This work would be of close relevance to rendering VO2-based devices operable in the wider temperature range. (C) 2019 Elsevier B.V. All rights reserved.