Manipulation of metal-insulator transition characteristics in aspect ratio-controlled VO2 micro-scale thin films on TiO2 (001) substrates

摘要

We manipulated the metal-insulator transition characteristics of VO2 thin films on TiO2 (001) substrates by changing their micro-scaled metallic domain configurations through size- and aspect ratio-control. A very steep resistance drop at 294?K was demonstrated for a 1D parallel domain configuration in a low aspect ratio sample, whereas a multi-level resistance change was exhibited for a 1D series domain configuration in a high aspect ratio sample. This difference was explained using simple resistor models. The results illustrate the importance of spatially distributed metallic domain positions in tuning electrical transport properties.