Preparation of polycrystalline VO2 films on glass and TiO 2/glass substrates by means of excimer laser assisted metal organic deposition

Abstract

An excimer laser assisted metal organic deposition process for the preparation of vanadium dioxide (VO2) films is described. When a precursor film grown on a silica glass substrate by preheating at 300°C was irradiated with a KrF laser at room temperature in air, the film was crystallized into polycrystalline VO2 phases. Generally, the preparation of VO2 films requires strict atmosphere control, but in this process, the polycrystalline VO2 films were successfully prepared without it. Moreover, it was revealed that crystallization into the VO2 phases was promoted by a TiO2 buffer layer placed on the glass substrate. This means that the photochemical reaction induced by the TiO2 absorbing the laser participates in the crystallization. The electrical resistivity of the film grown on the TiO2/glass substrate was lowered compared to that of the film grown on the glass substrate due to improvement of the film uniformity. The crystallinity of the obtained film was dependent on the irradiation time. With the improved crystallinity of the film, the resistivity drop through the metal-insulator transition became large. © 2010 The Ceramic Society of Japan. All rights reserved.