Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2016)
    Thin Films Tuesday Sessions
       Session TF-TuP

Paper TF-TuP12
Influence of Macro-Confinement on the Thermochromic Transition Temperature of VO2 Thin Films

Tuesday, December 13, 2016, 4:00 pm, Room Mauka

Session: Thin Films Poster Session
Presenter: Adetayo Adedeji, Elizabeth City State University, USA
Authors: A.V. Adedeji, Elizabeth City State University, USA
T. Patel, Elizabeth City State University, USA
A.D. Agyapong, Elizabeth City State University, USA
Correspondent: Click to Email
Vanadium dioxide (VO2) in bulk and thin film forms are well known thermochromic materials. VO2 switches optically from IR transparent to IR reflecting at a transition temperature of about 68ºC (about 150ºF). Because of the easily accessible transition temperature, researchers are interested in driving the transition temperature to lower or higher values depending on the intended application. The goal of this research is to investigate the effect of thin film macro-size confinement on the transition temperature of VO2. To achieve this goal, pure vanadium metal was deposited on clean quartz substrate using magnetron sputtering system. Different sizes of copper mesh were used as template for the depositions. The samples were oxidized in 800 mtorr N2/O2 gas mixture at 500°C for 4 hours. Surface morphology of the sample and chemical composition were obtained using SEM with EDS. Various grain sizes and orientations were observed at different depth from the quartz-VO2 interface with aberration corrected Scanning Tunneling Electron Microscope (STEM). Optical transmittance in air ambient was measured as the samples were taken through thermal cycle. It was observed that the transition temperatures of samples deposited through Cu meshes are different from those obtained from plain 2D VO2 films and films shielded with transparent Ta-Si-N barrier layer.