SiO_2溶胶在电沉积法制备CuInS_2薄膜中的作用

针对目前电沉积法制备的CuInS_2(CIS)薄膜存在S元素含量不足以及微观形貌差的问题,通过在普通镀液中加入SiO_2溶胶,采用一步电沉积技术在ITO导电玻璃上制备Cu-In-S预制薄膜,镀液的主要组成为金属盐、硫代硫酸钠和不同浓度SiO_2溶胶.在空气气氛中对Cu-In-S预制薄膜进行退火处理以获得多晶的CIS薄膜,并通过X射线衍射(XRD)、扫描电镜(SEM)、能量色散谱仪(EDS)及开路电位对CIS薄膜的结构、形貌、成分组成及光响应性能进行研究.结果表明:SiO_2溶胶浓度为4 mL/L时,得到的CIS薄膜的结晶度提高,同时,SiO_2溶胶作用下得到的CIS薄膜的表面形貌、成分组成和光响应性能都得到改善.因此,镀液中加入SiO_2溶胶有利于提高CIS薄膜的性能,尤其是浓度为4 mL/L时,性能提高得最为明显.

Effect of SiO_2 Sol on Performance of Electrodeposited CuInS_2 Thin Films

CuInS_2 (CIS) thin films with sufficient sulfur content and good morphology are hard to be grown by the present electrodeposition technique. In order to deal with the problem, Cu-In-S precursor thin films are prepared on ITO glass by the one-step electrodeposition technique in the electrolyte with SiO_2 sol. The electro-lytic bath used for the preparation of the thin films consists of metal salts, sodium thiosulfate (Na_2S_2O_3) and various concentrations of SiO_2 sol. Then the Cu-In-S precursor thin films are annealed in air-atmosphere to en-sure adequate crystallization of the CuInS_2 thin films. Samples are characterized using X-ray diffraction(XRD), scanning electron microscopy(SEM),energy dipersive spectroscopy(EDS) and open potential. It is found that films with higher crystallinity are achieved when the concentration of SiO_2 sol is 4 mL/L. Besides, the mor-phology, composition, and photoresponse performance are improved by adding SiO_2 sol in the electrolyte. The result of the investigation indicates that the performance of the CIS thin films can be improved by adding SiO_2 sol in the electrolyte, especially when the concentration of the SiO_2 is 4 mL/L.