Voltage-induced insulator-to-metal transition of hydrogen-treated NbO2 thin films

Abstract

We report on the voltage-induced insulator-to-metal transition (IMT) of the NbO2 thin films that are deposited under forming gas in the growth chamber. It is shown that the hydrogen in the forming gas gives rise to the abrupt voltage-induced IMT characteristics in NbO2 thin films that are sandwiched between top and bottom Pt electrodes. By a catalytic reaction at the triple boundary between NbO2 and Pt, hydrogen appears to be easily incorporated into the NbO2 lattice and doping significantly lowers the IMT temperature of NbO2 thin films, along with the reduction of NbO2 films.