Cd含量对Zn_(1-x)Cd_xO薄膜的结构、光学和电学性能的影响

Cd-composition Induced Effects on Structure,Optical and Electrical Properties of Zn_(1-x)Cd_xO Films

利用直流反应磁控溅射的方法和后退火技术在石英衬底上制备不同Cd含量的Zn_（1-x）Cd_xO（0≤x≤1）薄膜.利用XRD、XPS、TEM、Absorption及Hall等详细地对薄膜的结构、光学及电学性能进行了研究.研究发现：当x=0~0.2时,Zn_（1-x）Cd_xO薄膜为沿（002）方向择优生长的六角相结构;当x=0.5时,合金薄膜出现了六角相和立方相共存现象;当x≥0.8时,合金薄膜为沿（200）方向择优生长的立方相结构.结构为六角相时,合金薄膜的带隙从x=0时的3.25 e V减小到x=0.2时的2.75 e V;结构为立方相时,薄膜的带隙从x=0.8时的2.52 e V减小到x=1时的2.42 e V,带隙的变化很小.另外,霍尔测量结果表明,Cd含量对Zn_（1-x）Cd_xO薄膜的电学性质影响很大.

Zn1-xCdxO films with different Cd contents （0≤ x ≤1 ） were successfully deposited on quartz substrates by the direct current reactive magnetron sputtering and post-annealing techniques. The X-ray diffraction （ XRD）, X-ray photoelectron spectroscopy （ XPS）, transmission electron microscopy （ TEM）, optical absorption spectra and Hall were employed to investigate the structural, optical and electrical properties in detail. The Zn1-xCdxO film consisted of wurtzite phase with highly （002）-preferred orientation at x from 0 to 0. 2, mixture of wurtzite and cubic phases at x = 0.5, and cubic phase with highly （200） -preferred orientation at x≥0.8. The band gap decreased from 3.25 eV at x =0 to 2.75 eV at x =0.2 for the wurtzite Zn1-xCdxO, and decreased from 2.52 eV at x =0.8 to 2.42 eV atx= 1 ,which had a little change for cubic Zn1-xCdxO. In addition, Hall measurement results indicated that the influence of Cd content on the conduction behavior of Zn1-xCdxO films is significant.