La掺杂对CdS薄膜性能的影响

Influence of La-Doping on Electro-Optical Properties of CdS Thin Films

采用化学水浴法在玻璃衬底上制备了纯CdS薄膜和稀土La掺杂的CdS薄膜,在氮气气氛中对薄膜进行热处理。结果表明,未掺杂样品为立方闪锌矿CdS,La掺杂后衍射强峰仍为立方闪锌矿(111)晶向,但出现了微弱的六方纤锌矿结构,而且增强了短波光和近红外光的透过率,禁带宽度明显减小,同时La的掺入促进S元素百分含量的增加,使Cd/S更接近化学计量比。

The La-doped CdS films were grown by chemical bath deposition on glass substrates,and annealed in nitrogen environment.The impacts of the growth conditions,such as the solution concentrations,bath temperature,La contents,and annealing temperature,on its properties were evaluated.The La-doped CdS films were characterized with X-ray diffraction,and X-ray photoelectron spectroscopy.The results show that the La-doping significantly affects the microstructures and electro-optical properties of the CdS films.For example,the La-doping resulted in an observable transition from cubic to hexagonal phase,with（111） diffraction peak remaining unchanged;a narrower band-gap,and an increase of the S content,closer to the ideal stoichiometries of Cd and S.