Electro-thermal control of aluminum-doped zinc oxide/vanadium dioxide multilayered thin films for smart-device applications

We demonstrate the electro-thermal control of aluminum-doped zinc oxide (Al:ZnO) /vanadium dioxide (VO(2)) multilayered thin films, where the application of a small electric field enables precise control of the applied heat to the VO(2) thin film to induce its semiconductor-metal transition (SMT). The transparent conducting oxide nature of the top Al:ZnO film can be tuned to facilitate the fine control of the SMT of the VO(2) thin film and its associated properties. In addition, the Al:ZnO film provides a capping layer to the VO(2) thin film, which inhibits oxidation to a more energetically favorable and stable V(2)O(5) phase. It also decreases the SMT of the VO(2) thin film by approximately 5–10 °C because of an additional stress induced on the VO(2) thin film and/or an alteration of the oxygen vacancy concentration in the VO(2) thin film. These results have significant impacts on technological applications for both passive and active devices by exploiting this near-room-temperature SMT.