title: A uniform porous multilayer-junction thin film for enhanced gas-sensing performance.
abstract: Highly-uniform In2O3/CuO bilayer and multilayer porous thin films were successfully fabricated using a self-assembled soft template and a simple sputtering deposition technique. The sensor based on the In2O3/CuO bilayer porous thin film shows obviously improved sensing performance to ethanol at a lower working temperature, compared to its single layer counterpart sensors. The response of the In2O3/CuO bilayer sensors exhibit nearly 3 and 5 times higher performance than those of the single layer In2O3 and CuO porous film sensors over the same ethanol concentration, respectively. The sensing mechanism based on the p-n hetero-junction, which contributed to the enhanced sensing performance, was also experimentally confirmed by a control experiment in which an SiO2 insulation layer was inserted between the In2O3 and CuO layers to break the p-n junction. In addition, the sensing performance can be further enhanced by increasing the number of In2O3/CuO junction layers. The facile process can be easily extended to the fabrication of other semiconductor oxide gas sensors for practical sensing applications.
authors.affiliation: Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China. xhsun@suda.edu.cn.
authors.forename: Ping-Ping
authors.initials: PP
authors.lastname: Zhang
authors.affiliation: Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China. xhsun@suda.edu.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China. xhsun@suda.edu.cn.
authors.forename: Xu-Hui
authors.initials: XH
authors.lastname: Sun