Direct growth of VO2 nanoplatelets on glass and silicon by pulsed laser deposition through substrate temperature control

In this contribution, we explore the influence of substrate temperature on the phase evolution, morphology and transition properties of vanadium dioxide nanostructured thin films grown by pulsed laser deposition technique on glass and silicon substrates. The main objective is to grow directly on the top of substrates surface vanadium dioxide nanostructures with high density and high aspect ratio. Structural analysis using X-ray diffraction method showed highly oriented (011) VO2 films in the temperature range of 500-700 °C. Successfully, catalyst free and dense VO2 nanoplatelets were obtained at 600 and 700 °C. While the aspect ratio was limited for the nanoplatelets grown on silicon substrate, those grown on glass showed an aspect ratio of around 5. The study of the metal-insulator phase transition using a four probe technique evidenced the effect of the growth temperature on the transition properties through its influence on the stoichiometry, grain size and shape. Mechanisms behind the growth of elongated VO2 nanoplatelets on glass substrate are evidenced throughout substrate nature influence. The amorphous nature of glass which acts as a free standing environment at high temperature is suggested to be the key factor to grow elongated nanoplatelets in an open structure of particular morphology. As summary, using pulsed laser deposition, we have established a one-step growth protocol of dense VO2 nanoplatelets with a high surface-to-volume ratio which can find a potential application in gas sensing devices.