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本文从理论与实验两方面入手,对高价态差金属W掺杂ZnO(WZO)薄膜材料的特性进行分析讨论.采用基于密度泛函理论的平面波赝势方法对WZO材料特性进行理论分析,计算结果表明:W以替位形式掺入ZnO六角纤锌矿晶格结构中,由于W—O键的键长较长引起晶格常数增加,产生晶格畸变;掺杂后费米能级进入导带,其附近的导电电子主要由W 5d,O 2p及Zn 3d电子轨道提供,材料表现出n型半导体的特性;同时能带简并效应使其光学带隙展宽.为进一步验证该理论分析结果的适用性,本文采用脉冲直流磁控溅射技术进行了本征ZnO及WZO薄膜的实验研究,结果表明:W掺入未改变ZnO的生长方式,但引起薄膜的晶格常数增加,电阻率由本征ZnO的1.35×10~(-2)Ω·cm减小到1.55×10~(-3)Ω·cm,光学带隙由3.27 eV展宽到3.48 eV.制备的WZO薄膜在400-1100 nm的平均透过率大于83%.实验结果对理论计算结果进行了验证,表明WZO薄膜作为透明导电薄膜的应用潜力.
In this paper, the properties of W-doped ZnO (WZO) thin films with high valence states are analyzed and discussed from both theoretical and experimental aspects.The theoretical analysis of the properties of WZO materials is carried out by using plane wave pseudopotential method based on density functional theory The results show that: W as a substitute for the incorporation of ZnO hexagonal wurtzite lattice structure, due to W-O bond length longer lead to an increase in the lattice constant, resulting in lattice distortion; after the Fermi level into the conduction band , The nearby conductive electrons are mainly provided by the W 5d, O 2p and Zn 3d electron orbitals, and the material exhibits the characteristics of n-type semiconductors; meanwhile, the degenerated band gap can be broadened with the degenerate effect of the band.In order to verify the theoretical analysis results In this paper, the pulsed DC Magnetron Sputtering technique was used to investigate the intrinsic ZnO and WZO films. The results show that the W doping did not change the growth mode of ZnO, but the lattice constants of the films increased, The 1.35 × 10 -2 Ω · cm of ZnO decreased to 1.55 × 10 -3 Ω · cm and the optical band gap broadened from 3.27 eV to 3.48 eV.The average WZO films prepared at 400-1100 nm Transmission rate is greater than 83%. Experimental results The theoretical calculation results were validated, indicating that WZO Film as a transparent conductive thin film of potential applications.