采用化学浴沉积法将氯化镉、氯化铵、硫脲和氨水的溶液体系合成CdS薄膜,用扫描电子显微镜、X射线衍射仪和紫外可见吸收光谱等研究了CdS薄膜的形貌、相结构和光学性能,通过测试薄膜的光电流响应曲线分析了薄膜的光电性能.结果表明:溶液的pH值在9~11的范围内均可以制备均匀致密的CdS薄膜,其中pH=10时制备的CdS薄膜最为均匀致密且其X射线衍射仪衍射峰强度最强,对应的光学带隙约为2.37 eV;光电流响应曲线显示该薄膜的光电导最高为2.94×10-2 Ω-1·cm-1,光暗电导比为38.23,具有最佳的光敏性.

The CdS thin films were prepared by chemical bath deposition in a solution containing cadmium chloride,ammonium chloride,thiourea and ammonia.The morphological,structural and optical properties of CdS films were investigated by scanning electron microscope,X-ray diffraction and UV-vis-NIR spectroscopy.The photo-current response curves were also tested to study the optoelectrical performance of the films.It was found that uniform and compact CdS films could be prepared using pH values from 9 to 11.The CdS film prepared at pH=10 showed a most dense surface morphology and presented strongest peak intensities of the X-ray diffraction patterns and a band gap of about 2.37eV.According to photo-current response results,the CdS film with best quality has a highest photoconductivity of 2.94×10-2 Ω-1·cm-1 and a largest light and dark conductivity ratio of 38.23.