Thermochromic VO_2 coatings for smart window applications

摘要

Vanadium Dioxide (VO_2) is a smart material which exhibits a phase transformation at a temperature of 68℃ in its pure and single crystalline form. The phase transition from the monoclinic semiconducting form to the tetragonal metallic (rutile) form is also accompanied by a change in the optical properties of VO_2. This simultaneous optical shift goes from an optically transparent to an optically opaque material where a change in solar radiation transmittance is observed. Although the introduction of a dopant into the lattice structure of VO_2 has proven to decrease the transition temperature to near room temperature, the optical transmittance capability as well as the nature of the transition remains a challenge. This research project involves the development of a doped VO_2 coating for smart window applications with enhanced optical and thermochromic properties. Multiple layer depositions will be explored in addition to the use of transition metal alloys in order to achieve improved switching and optical properties. Various physical characterization techniques as well as electrochemical analyses will be implemented in order to gain a better understanding of the material developed.