ILGAR法制备CdS薄膜新工艺的研究

STUDY ON A NOVEL ILGAR TECHNOLOGY FOR CdS TfflN FILM

采用一种薄膜制备的新方法一离子层气相反应法(ILGAR),以CdCl2为前驱体,H2S为硫源制备了CdS薄膜。利用XRD、SEM、AFM、XPS及UV-VIS透射光谱等测试分析方法对薄膜的晶型、表面化学组成、表面形貌、膜厚增长速度及光学性能进行了研究。实验结果表明:ILGAR法制备的CdS薄膜表面较致密、均匀、附着性好;在0.05MCdCl2前驱体溶液浸渍处理,薄膜以-2.8nm/cycle的恒定速率增长,且薄膜晶体沿立方(111)面具有明显的择优取向生长;400℃热处理1h,发生立方→六方晶型转变,最终为六方与立方混相结构,择优方向转为六方(002)面;薄膜经热处理后在可见光处的吸收峰发生红移,其禁带宽度降低,并且会随着膜厚的增加进一步降低。

A novel technology, ion layer gas reaction (ILGAR), was applied to prepare CdS thin film on glass slide at ambient temperature. XRD, SEM, XPS, AFM and UV-VIS were used to characterize structure, superficial components and topography, deposited rate and optical properties of CdS thin films. The result showed that CdS thin films deposited by ILGAR are homogenous and compact and good in adhesion to substrate. As-deposited CdS thin film prepared by 0.05 M CdCl2 precursor concentration, which are predominately of cubic blende crystal structure with preferred orientation along (111) reflection with 2.8 nm/cycle constant growth rate, mainly transforms into hexagonal wurtzite crystal structure with strong c-axis preferential orientation after annealing at 400°C for 1 h. The optical absorption edge of annealed CdS thin film shifts to higher wavelength indicated a decrease in the band gap while band gap decreases with increasing thickness of films.