Ifluence of grain boundary tunneling on the resistivity of the VO2 films prepared by sol-gel method

Based on the model of the two phases of grain and grain boundary, the grain boundary tunneling of carriers was considered to simulate the change of the resistivity of VO2 polycrystalline film prepared by Sol-gel method in temperature range of 10degreesC similar to 100degreesC. The simulation results were in good agreement with the experiment data. The results indicate that the grain boundary effect decreases the magnitude of resistivity change of VO2 film durying semiconductor-to-metal phase transition, and meanwhile the VO2 film in metal phase has a negative temperature coefficient of resistivity.