Studies of the cathodic electrodeposition of CdS from aqueous solution

✍ Scribed by Stephen Dennison

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 703 KB
• Volume: 38
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(93)85108-b

✦ Synopsis

The cathodic electrodeposition of CdS from aqueous solutions of Cd 2 + and $2 O2-at 90°C, has been investigated using a combination of voltammetric and galvanostatic techniques. It was found that the overall deposition is an EC-type mechanism, where the initial, electrochemical step is the reduction of Cd 2÷. This is followed by the reaction of $20 2-with the reduced Cd species, which is the rate-determining step. The presence in the electrolyte of both Cd 2+ and $2 O2-at 90°C results in the spontaneous formation of finely-divided CdS and a decrease in solution pH. The lower pH increases the rate of the chemical reaction of the EC process, shown by the increase in CdS film thickness as pH decreases. Lower pH also promotes a low potential process which interferes with both controlledpotential and controlled-current CdS growth.