Characteristics of the Phase Transition in Vanadium Dioxide Films Obtained via Chemical Vapor Deposition

Abstract

Changes in the characteristics of the semiconductor–metal phase transition in VO2 polycrystalline films obtained via chemical vapor deposition from vanadyl acetylacetonate vapor and oxygen with the temperature of synthesis varying from 373 to 473°C and the oxygen pressure varying from 25 to 90 sccm were studied. The critical temperature of the phase transition and the width of the hysteresis are calculated from the temperature dependences of the films’ coefficients of reflection. These dependences are determined using a special spectrophotometric system during the thermal cycling of the samples from room temperature to 100°C. The relationship between the phase transition characteristics and the phase composition and texture of the films is established. It is found that the critical temperature and the narrowest hysteresis correspond to films containing single monoclinic phase VO2(M1) with the preferential orientation (texture) of crystallites in the (011) plane.