用化学沉积方法在沉积温度为90℃下制备了CdS薄膜。研究了直接退火处理和涂敷CdCl2甲醇饱和溶液后退火处理对CdS薄膜的影响。利用X射线衍射、扫描电子显微镜对薄膜的晶体结构、表面形貌进行了研究,发现没有任何处理的CdS薄膜没有明显的晶型;直接退火处理促进了CdS立方相的结晶,晶粒没有增大且生长出许多细小的晶粒;涂敷CdCl2甲醇饱和溶液后退火处理不仅极大地促进了CdS六角相的结晶,而且晶粒增粗增大,表面更加光滑。用吸收光谱研究了薄膜的光学特性,发现退火使薄膜的禁带宽度变窄,涂敷CdCl2甲醇溶液后退火处理使吸收边变陡和带尾变小。表明涂敷CdCl2甲醇溶液退火处理明显改善CdS薄膜的结晶质量和光学性质。
CdS thin films were prepared by chemical bath deposition (CBD) at 90 ℃ .The influence of annealing and CdCl2 treatment on CBD-CdS thin film was studied. XRD and SEM were used to study the crystal structure and surface morphology of the films. The untreated CBD-CdS films had poor crystallinity; the CdS thin film made with annealing treatment had cubic crystallinity but small grain size. After the CdCl2 treatment, these films recrystallized to the hexagonal phase, resulting in a better crystallinity, and smooth surface morphology. Optical properties were studied by absorption spectrum. The energy gap of the films was found to decrease by annealing, and the CBD-CdS made with CdCl2 treatment had a lower density of planar defects. In conclusion, the CdCl2 treatment can improve the properties of the CdS thin films.