【作者】 华缜；

【导师】 靳正国；

【作者基本信息】 天津大学 ， 材料学， 2004， 硕士

【摘要】 本文采用电化学沉积法，首次以硫酸铜和硫氰酸钾的水溶液为前驱体原料，在ITO导电玻璃上沉积出了性能良好的p-CuSCN半导体薄膜。考察了各种工艺参数对CuSCN薄膜的性能的影响，对电沉积过程中的伏安特性进行了综合分析，确定了电沉积的最佳条件。对于电沉积过程中薄膜生长机理进行了初步的探讨。硫酸铜与硫氰酸钾的混合水溶液极不稳定，先生成棕色的Cu（SCN）2沉淀，再转变为白色的CuSCN沉淀。络合剂的加入使硫酸铜和硫氰酸钾的混合水溶液能作为稳定的电沉积溶液。经考察EDTA是本实验最合适的络合剂，且加入EDTA的电沉积溶液放置几天后再沉积对提高成膜质量有利。利用线性伏安法考察了电沉积溶液的电化学性质，确定合适的沉积电位，并记录电沉积过程的伏安特性。电沉积溶液中SCN-的含量、沉积电位、溶液的浓度等都是影响薄膜性能的重要因素。当Cu2+的浓度固定时，溶液中摩尔比Cu／SCN＝2：1时薄膜的形貌最好，薄膜中SCN的化学计量比随着溶液中SCN-含量的增大而增大，且呈线性关系；在200mv—-500mv的电位范围内可以避免沉积p-CuSCN薄膜时金属单质的生成，沉积电位过正时（超过200mv），不能沉积上薄膜，沉积电位比-500mv更负时发生金属铜和CuSCN共沉积，最佳的沉积电位为-500mv；浓度过大或过小都不利于沉积，试验确定合适的浓度为0.01－0.02mol/l。电沉积过程中薄膜的生长机理是基于电子跃迁的隧道效应和半导体／电解液界面的双电层结构。更多还原

【Abstract】 CuSCN thin films were prepared by electrochemical deposition method in aqueous solutions using cupric sulphate and potassium thiocyanate as precursor materials. The effects of processing parameters on properties of thin films were studied and growth mechanism of film was discussed fundamentally. Process of the deposition was measured by voltammetry on potentiostat and the best condition of deposition was confirmed. The mixture of cupric sulphate aqueous solution and potassium thiocyanate aqueous solution is too instable to be used as electrolyte solution. Chelation mechanism, using ammonia, cetric acid and EDTA as chelated reagent, was used to obtain stable electrolyte solution. It is found that EDTA is the optimal chelated reagent and the solution with EDTA stayed for a few days is better for deposition.The linear sweep voltammetry is used to confirm the deposition potentials and test the process of deposition.Content of the SCN- in electrolyte solution, deposition potential and concentration of solution are important factors on quality of films. Morphology of the films deposited through the aquoues electrolyte solution with mol ratio Cu2+/SCN-=2:1 is best. Content of the SCN in film is increasing as the enhancement of content of the SCN- in solution. Single phase p-CuSCN thin films can be deposited on the potential range from 200mv to -500mv. It is difficult to deposited film when deposition potential is higher than 200mv. If deposition potential becomes too negative, e.g. below -600mv, Cu will be co-deposited out. The optimal potential is -500mv.The suitable concentration is between 0.01mol/L and 0.02mol/L.The deposition mechanism is based on the tunneling of electron transition and double electrical layer of interface between semiconductor and electrolyte.更多还原