文献类型：期刊文献

英文题名：Dependence of the Nitrogen Dioxide (NO2) Sensitivity of SnOx-Sn/Graphene Gas Sensors on Vacuum Annealing and Ultraviolet (UV) Ozone Exposure

作者：Mu, Haichuan[1];Wang, Keke[1];Xie, Haifen[1]

机构：[1]East China Univ Sci & Technol, Sch Sci, Dept Phys, Shanghai 200237, Shanghai, Peoples R China

年份：2017

卷号：17

期号：2

起止页码：1480

外文期刊名：JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY

收录：;EI(收录号：20170403284414);WOS:【SCI-EXPANDED(收录号:WOS:000397118700087)】；

语种：英文

外文关键词：Graphene; SnOx-Sn Compound Films; NO2 Sensitivity

摘要：Tin oxides and tin (SnOx-Sn) compound films were thermally evaporated onto chemical vapor deposition (CVD)-grown graphene films to obtain improved nitrogen dioxide (NO2) gas sensitivity. The effects of the vacuum annealing and ultraviolet (UV) ozone (O-3) exposure of the bare graphene films prior to the thermal evaporation on the SnOx-Sn films' sensitivities, bonding states, and surface morphologies were investigated. With increasing annealing time, the coverage of the SnOx-Sn nanoparticles on the graphene increased and the p to n sensitivity transition occurred when n-type SnOx-Sn nanoparticles became dominant instead of the p-type graphene films for sensors without O-3 exposure. Meanwhile, the opposite p-type sensitivity response was dominant with increasing annealing time for the O-3-treated sensors. The chemisorbed Sn on the graphene generated by O-3 exposure was oxidized by highly reactive NO2, resulting in a p-type doping effect, which would lead to n-to p-type sensitivity transition when the hole concentration exceeded the initial electron concentration of the n-type SnOx-Sn compound films. Vacuum annealing and O-3 exposure also exhibited a tremendous influence on the SnOx-Sn films' surface morphologies, which could be responsible for the subsequent sensitivity dependence.