Hall measurement of ultra thin vanadium dioxide thin films

In this work, we present the investigation of temperature dependent hall measurement of the ultra thin VO$_2$ films grown on Si/SiO$_2$ substrate. Experimental results suggest that electrons are the predominant carrier both in the semiconducting and metallic phases. The decrease of the resistivity with increasing temperature is mainly caused by the increase in the number density of charge carriers. The temperature dependence of the carrier concentration indicates the VO$_2$ films has a band gap of 0.40$\pm$0.09 $ev$ in the semiconducting phase. Analysis of hall effect data based on a composite cube model suggests that the sample has some untransitional phase with a length that is 1/4 of the grains.