溶液激发方式对化学水浴法沉积CdS薄膜生长的影响

Structural and Morphological Evolution Studies of CdS Thin Films Prepared by Chemical Bath Deposition by Different Agitation Methods

化学水浴法是目前制备CdS薄膜的主流方法之一,其中对溶液实施不同的溶液激发方式会对薄膜的性能产生很大影响。采用4种不同的溶液激发方式:搅拌法、静置法、超声法、摇晃法以化学水浴法沉积了CdS薄膜。采用台阶仪、X射线衍射仪、扫描电子显微镜和原子力显微镜等系统地研究了这4种不同的溶液激发方式对CdS薄膜的生长速度、晶体结构与表面形貌的影响。实验结果表明,随着沉积时间增加,CdS薄膜的厚度都会逐渐增加并最终趋于一恒定值。搅拌法与摇晃法制备的CdS薄膜具有更快的生长速度、更大的颗粒尺寸以及更加粗糙的表面形貌。采用静置法沉积薄膜在沉积时间较短时,薄膜表面存在大面积的由尺寸12 nm的小颗粒构成的区域。随着沉积时间增加,该区域面积逐渐减小进而消失。通过对薄膜表面形貌随沉积时间增加的演化过程的研究,在一定浓度下CdS薄膜的生长是离子-离子生长机制。通过对比不同溶液激发方式沉积的CdS薄膜的表面形貌,分析了不同溶液激发方式对CdS薄膜形貌的影响。

Chemical bath deposition was one of the most important methods to prepare CdS films. The properties of CdS films could be substantially influenced by the solution agitation methods. CdS films were prepared by chemical bath deposition： stirring, without solution agitation, ultrasonication and vibration, respectively. The growth rate, structural and morphological properties of CdS films prepared by different solution agitation methods were investigated by profilometer, X-ray diffraction （XRD）, scanning electron micro- scope（SEM） and atomic force microscope（AFM）, respectively. As the deposition time increased, the film thickness increased corre- spondingly and finally came to saturation. The CdS films prepared by stirring and vibration had higher growth rate, larger grain size and rougher surface morphologies. When the CdS films were prepared by without solution agitation at short deposition time, large area of the region consisted of small grains with size of 12 um. As the deposition time increased, the area of this region decreased and finally disap- peared. According to the morphological evolution of CdS films with deposition time, it could be inferred that the growth of CdS films was dominated by ion-by-ion mechanism at certain reactant concentration. The influence of different solution agitation methods on the CdS films morphologies was analyzed by the comparison of the CdS thin films prepared by different solution agitation methods.