title: Fabrication of highly sensitive and selective H₂ gas sensor based on SnO₂ thin film sensitized with microsized Pd islands.
abstract: Ultrasensitive and selective hydrogen gas sensor is vital component in safe use of hydrogen that requires a detection and alarm of leakage. Herein, we fabricated a H2 sensing devices by adopting a simple design of planar-type structure sensor in which the heater, electrode, and sensing layer were patterned on the front side of a silicon wafer. The SnO2 thin film-based sensors that were sensitized with microsized Pd islands were fabricated at a wafer-scale by using a sputtering system combined with micro-electronic techniques. The thicknesses of SnO2 thin film and microsized Pd islands were optimized to maximize the sensing performance of the devices. The optimized sensor could be used for monitoring hydrogen gas at low concentrations of 25-250 ppm, with a linear dependence to H2 concentration and a fast response and recovery time. The sensor also showed excellent selectivity for monitoring H2 among other gases, such as CO, NH3, and LPG, and satisfactory characteristics for ensuring safety in handling hydrogen. The hydrogen sensing characteristics of the sensors sensitized with Pt and Au islands were also studied to clarify the sensing mechanisms.
authors.affiliation: International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No. 1, Dai Co Viet Road, Hanoi, Viet Nam.
authors.forename: Van Toan
authors.initials: VT
authors.lastname: Nguyen
authors.affiliation: International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No. 1, Dai Co Viet Road, Hanoi, Viet Nam.
authors.forename: Viet Chien
authors.initials: VC
authors.lastname: Nguyen
authors.affiliation: International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No. 1, Dai Co Viet Road, Hanoi, Viet Nam.
authors.forename: Van Duy
authors.initials: VD
authors.lastname: Nguyen
authors.affiliation: School of Electrical Engineering (SEE), Hanoi University of Science and Technology (HUST), Hanoi, Viet Nam.
authors.forename: Si Hong
authors.initials: SH
authors.lastname: Hoang
authors.affiliation: Division of Microsystems Technology, Department of Engineering Sciences, Uppsala University, 75237 Uppsala, Sweden.
authors.forename: Nguyen
authors.initials: N
authors.lastname: Hugo
authors.affiliation: International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No. 1, Dai Co Viet Road, Hanoi, Viet Nam.
authors.forename: Duc Hoa
authors.initials: DH
authors.lastname: Nguyen
authors.affiliation: International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No. 1, Dai Co Viet Road, Hanoi, Viet Nam. Electronic address: hieu@itims.edu.vn.
authors.forename: Van Hieu
authors.initials: VH
authors.lastname: Nguyen
keywords: H(2) gas sensor; Pd islands; SnO(2); Sputtering; Wafer-scale fabrication