后退火工艺对Ga掺杂Zn1-xCdxO薄膜光学和电学性能的影响.docVIP

 5 10 15 20 25 30 35 40 45  Post annealing effect on optical and electrical properties of Ga-doped Zn1-xCdxO thin films# DUAN Libing, ZHAO Xiaoru, LIU Jinming, GENG Wangchang, ZHANG Fuli, SHI Xiaolong, SUN Huinan* (Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education of China and School of Science, Northwestern Polytechnical University, Xi’an 710072) Abstract: (Cd,Ga)-codoped ZnO thin films were prepared by sol-gel method. The codoping films retained wurtzite structure of ZnO, and showed preferential c-axis orientation. The effects of post annealing ambient (in vacuum and nitrogen) on the optical and electrical properties of the films were investigated. The transmittances of the films were obviously degraded by vacuum annealing to 60-70%, but enhanced to 80-90% after nitrogen annealing, which were about 10% higher than those of (Cd,Al)-codoped ZnO films. The carrier concentration increased, while resistivity decreased with narrowing band gap of Ga-doped Zn1-xCdxO, i.e. the conductivity is also improved by Cd codoping. The resistivity of nitrogen annealing films is one order higher than that of vacuum annealing films, i.e. the transmittance and conductivity of the films seem irreconcilable, and the trade-off between transmittance and conductivity could be effectively controlled by post annealing ambient. Both the Cd doping (majority) and Burstein-Moss effect (minority) affect the band gap (Eg) modification. Due to the ionic radius of Ga3+ is closer to that of Zn2+ than Al3+, and hence less deformation of ZnO lattice after Ga doping, in view of transmittance and conductivity, Ga might be a more appropriate dopant for our band gap engineering transparent conducting oxide (TCO) films than Al. Keywords: Inorganic nonmetallic materials; ZnO films-based Transparent conducting; Band gap engineering; post annealing 0 Introduction Transparent conducting oxide (TCO) films, which are characterized by a unique combination of low electrical resistivit