title: Crack-free periodic porous thin films assisted by plasma irradiation at low temperature and their enhanced gas-sensing performance.
abstract: Homogenous thin films are preferable for high-performance gas sensors because of their remarkable reproducibility and long-term stability. In this work, a low-temperature fabrication route is presented to prepare crack-free and homogenous metal oxide periodic porous thin films by oxygen plasma irradiation instead of high temperature annealing by using a sacrificial colloidal template. Rutile SnO2 is taken as an example to demonstrate the validity of this route. The crack-free and homogenous porous thin films are successfully synthesized on the substrates in situ with electrodes. The SnO2 porous thin film obtained by plasma irradiation is rich in surface OH groups and hence superhydrophilic. It exhibits a more homogenous structure and lower resistance than porous films generated by annealing. More importantly, such thin films display higher sensitivity, a lower detection threshold (100 ppb to acetone) and better durability than those that have been directly annealed, resulting in enhanced gas-sensing performance. The presented method could be applied to synthesize other metal oxide homogenous thin films and to fabricate gas-sensing devices with high performances.
authors.affiliation: Key Lab of Materials Physics, Anhui Key Lab of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (P.R. China), Fax: (+86) 551-65591434.
authors.forename: Zhengfei
authors.initials: Z
authors.lastname: Dai
authors.forename: Lichao
authors.initials: L
authors.lastname: Jia
authors.forename: Guotao
authors.initials: G
authors.lastname: Duan
authors.forename: Yue
authors.initials: Y
authors.lastname: Li
authors.forename: Hongwen
authors.initials: H
authors.lastname: Zhang
authors.forename: Jingjing
authors.initials: J
authors.lastname: Wang
authors.forename: Jinlian
authors.initials: J
authors.lastname: Hu
authors.forename: Weiping
authors.initials: W
authors.lastname: Cai
keywords: crack-free; low temperature; plasma chemistry; porous thin films; sensors