基于团簇加连接原子模型定量分析阳离子掺杂ZnO电子载流子浓度

Electron Carrier Concentration of Cation Doped ZnO by Cluster Plus Glue Atom Model

目的定量分析阳离子掺杂ZnO材料中最优化阳离子掺杂量及电子载流子浓度。方法基于团簇加连接原子模型,解析并建立阳离子掺杂ZnO材料的团簇式结构,计算最优阳离子掺杂量条件下的电子载流子浓度。根据理论分析结果,设计Sn掺杂ZnO材料,并利用磁控溅射方法制备Sn掺杂ZnO薄膜。通过紫外可见分光光度计、霍尔效应测试仪等分别评价Sn掺杂ZnO薄膜的透光率和电子载流子浓度。结果以纤锌矿ZnO为研究体系,基于团簇加连接原子模型,建立纤锌矿ZnO的团簇式{[Zn-O4]Zn3}。在此基础上,建立纤锌矿ZnO超团簇结构:{中心团簇式}-{第一近邻团簇式}6-{连接团簇式}={[Zn-O4]Zn3}-{[Zn-O4]Zn3}6-{[Zn-O4]Zn3}=Zn32O32。基于纤锌矿ZnO超团簇结构,建立阳离子掺杂ZnO的超团簇结构{[M-O4]Zn3}-{{[M-O4]Zn3}{[Zn-O4]Zn3}5}-{[M-O4]Zn3}=M3Zn29O32,给出最优化元素配比AM︰AZn=10.34%。根据阳离子掺杂ZnO的超团簇结构M3Zn29O32,定量计算出Al3Zn29O32的最优化电子载流子浓度为3.935×10^21 cm^–3,并分析实际应用的AlZn31O32薄膜的电子载流子浓度仅为最优化理论值1/10的原因。最终,设计并制备SnZn31O32薄膜,其在可见光波段(450~800nm)的平均透光率为80.25%±1.74%,电子载流子浓度为(7.72±1.68)×10^20 cm^–3。结论团簇加连接原子模型能够定量解析阳离子掺杂ZnO材料体系中掺杂量与电子载流子浓度,可为设计高性能阳离子掺杂ZnO材料提供理论指导。基于团簇加连接原子模型设计的SnZn31O32薄膜,具备透明导电性质,通过进一步的研究,有望成为具有高电子载流子浓度的新型透明导电氧化物材料。

The paper aims to quantitatively analyze the ideal cation doping concentration and ideal electron carrier concentration in cation doped wurtzite ZnO.Based on the cluster plus glue atom model,the culster formular of wurtzite ZnO was established to calculate the electron carrier concentration under the ideal cation doping concentration condition.The Sn-doped ZnO material was designed according to the result of theoritical analysis and the Sn-doped ZnO film was prepared by the magnetron sputtering method.The transmittance and electron carrier concentration of the Sn-doped ZnO film were respectively evaluated with ultraviolet and visible spectrophotometer,Hall effect measurement system,etc.With wurtzite phase ZnO as a research system and based on the cluster plus glue atom model,the clustuer structure{[Zn-O4]Zn3}of wurtzite phase ZnO was evaluated.On this basis,the super clustur structure of wurtzite phase ZnO was established,which consisted of one center culster formular,six nearest culster formular,and one glue culster formular,just as expressed as{[Zn-O4]Zn3}-{[Zn-O4]Zn3}6-{[Zn-O4]Zn3}=Zn32O32.Based on the super clustur structure of wurtzite phase ZnO,the super clustur structure of cation doped ZnO was established,which could be expressed as{[M-O4]Zn3}-{{[M-O4]Zn3}{[Zn-O4]Zn3}5}-{[M-O4]Zn3}=M3Zn29O32,with the optimum element ratio of AM:AZn=10.34%.According to the super clustur structure of cation doped ZnO,the ideal electron carrier concentration of unit cluster Al3Zn29O32 was quantitively calcuated to be 3.935×10^21 cm^–3.In practice,Al doped ZnO displayed the unit cluster AlZn31O32 and about 4×10^20 cm^–3 in electron carrier concentration,which was about 1/10 of ideal value.The reasons were discussed in details.SnZn31O32 film was designed and prepared.It dispalyed the average transmissivity of 80.25%±1.74%in wavelength range in 450~800 nm and electron carrier concentration(7.72±1.68)×10^20 cm^–3.In summary,the cluster plus glue atom model could quantitatively analyze the doping content and the electron carrier concentration of cation doped ZnO.It can provide theoritical guidance for design cation doped ZnO materrial of high performance.The SnZn31O32 film designed based on the cluster plus glue atom model is transparent and conductive.With further research,it could be the ideal transparent conductive oxide film with high electron carrier concentration in the future.