溶胶-凝胶法制备掺镉ZnO薄膜及光学禁带研究

The Preparation of Cd-doped ZnO Thin Films by Sol-Gel Technique and Its Optical Bandgap Investigation

主要研究掺镉ZnO薄膜的光学禁带。采用溶胶－凝胶（Sol—Gel）旋转涂覆法，在Si（100）上生长掺镉ZnO薄膜，对薄膜的XRD分析表明，掺镉ZnO薄膜仍为六角纤锌矿结构，并沿C轴择优取向生长。通过实验优化出本工艺条件下的较佳参数：退火温度为800℃，x（Cd）－6％～8％；以普通玻璃为基片的透射光谱表明掺镉ZnO薄膜的禁带宽度约为3．22eV，比纯ZnO晶体禁带宽度3．30eV明显减小，适度掺镉可降低薄膜的光学禁带宽度。

The Cd-doped zinc oxide film was prepared on Si （100） substrate by the Sol-Gel process using a spin ning-technique. The XRD analysis showed that the Cd-doped ZnO film had a hexagonal wurtzite structure and was grown preferentially along c-axis orientation. The better technical parameters were obtained through optimizing the process,that was,the annealing temperature was 800 ℃ and the Cd-doped concentration was at the range of 6% 8%. The optical transmission spectrum of the Cd-doped ZnO film on glass substrate indicated that the band-gap width of the thin film was 3.22 eV. This band-gap width was narrower than that of ZnO bulk crystal （the band-gap width of ZnO crystal was 3.30 eV）. It was practicable to reduce the optical bandgap width of the thin film by Cd-doping appropriately.