Sb掺杂ZTO透明导电薄膜的结构和性能

Structures and Properties of Sb-Doped ZTO Transparent Conducting Films

采用溶胶凝胶法和旋涂法制备Sb掺杂钙钛矿结构ZTO(ZnSnO_3)透明电薄膜,并借助XRD、SEM、XPS、UV-Vis和Hall效应测试等手段研究了其结构和性能。比较了Sb离子单独置换ZnSnO_3晶体中的Zn2+或Sn4+,以及同时置换Zn2+和Sn4+等3种置换方式所得薄膜的结晶状态,分析了不同置换方式形成的薄膜中Sb离子实际占有的晶格位置,以及Sb5+与Sb^(3+)的比例变化。探讨了不同置换方式晶体中氧空位(VO)、锌间隙(Zni)和锡离子变价(SnSn″)等结构缺陷相应的含量变化,并研究Sb离子掺杂浓度对薄膜晶体结构、结构缺陷和电阻率的影响。研究表明,3种置换方式的Sb掺杂ZTO薄膜均保持单一ZnSnO_3晶相,并且Sb离子均按设计的方案进入了相应的晶格位置,但不同置换方式的薄膜中,Sb5+与Sb^(3+)的比例不同,并且会随Sb离子浓度增大而逐渐减小。研究证明Sb离子置换方式以及掺杂浓度均会显著影响薄膜中载流子的浓度和迁移率,从而影响其电性能。在所制备的薄膜中,Sb离子单独置换Zn2+且组成为Sb_(0.15)Zn_(0.35)Sn_(0.5)O_(1.5)的薄膜电阻率最低,为0.423Ω·cm。此外,所有Sb掺杂ZTO薄膜在360~800 nm波长范围内透过率均在78%以上。

Sb-doped ZTO（ZnSnO3） transparent conducting films were synthesized by sol-gel spin-coating method.The structures and properties of Sb-doped ZTO films were characterized by XRD,SEM,XPS,UV-Vis and Hall effect measurements.Three Sb-doping methods, including the substitution of either Zn2＋or Sn4＋, or both the two ions in ZnSnO3 were adopted.The crystalline features, the lattice positions of Sb ion and the ratios of Sb5 ＋and Sb3 ＋in Sb-doped ZTO films prepared by different substitution methods were investigated.Followed by a comprehensive comparison of the amount of oxygen vacancy（VO··）, interstitial zinc（Zni··） and stannous ion（SnSn″）,the effects of Sb-doping concentrations on the crystal structure, the defects, and the electrical properties of the films in different methods were detected.Experimental results indicated that the perovskite structure of the ZnSnO3 crystal has not been disturbed by Sb-doping.Moreover, the Sb ions successfully occupied the corresponding positions of the ZnSnO3 lattice as expected, with varying molar ratios（nSb5＋/nSb-（3＋）） among the methods.That is, the nSb5＋/nSb-（3＋）decreased with the increase of the doping concentration.It has been concluded that the carrier concentrations and mobility were influenced by both the substitution methods and the Sb-doping concentrations, resulting in the variation of the conductivity of the films.Among all films, the Sb0.15Zn0.35Sn0.5O1.5film obtained a minimum resistivity of 0.423 Ω·cm.Finally, the transmittance of all the as-prepared films were higher than 78% within the 350-800 nm range being demonstrated.