CdSe电沉积层的组成及形成机理

伏安曲线和现场光电流测定用于研究在钛基体上阴极电沉积形成Cdse薄膜的机理. XPS实验表明, CdSe沉积层的组成与沉积电位、沉积时间和溶液组成有关.在0.1 mol·L~(-1)CdSO_4+4 mmol·L~(-1)H_2SeO_3+0.2 mol·L~(-1) H_2SO_4溶液中, 当电位比-0.50 V正时生成富Se层, 而当电位比-0.70 V还负时生成富Cd层. 在-0.69 V下沉积, 沉积层的Se/Cd计量比接近1.1. 在同一电位下, 若提高H_2Se0_3浓度, 则沉积物中Se的含量增多. 实验结果表明, CdSe电沉积因条件不同遵循两种不同的机理, 据此讨论了克服Se/Cd比大于1的可能措施。

The Composition and Formation Mechanism of Electrodeposited CdSe Films

The cathodic deposition mechanism of CdSe films on Ti substrates was investigated using cyclic voltammetry and in-situ photocurrent mesurements. XPS analysis showed that CdSe film composition depends on deposition potentials, deposition time and concentration of H_2SeO_3 in the bath. It was found that in 0.1 mol·L~(-1) CdSO_4+4 mmol·L~(-1) H_2SeO_3+0.2 mol·L~(-1) H_2SO_4, the deposits formed at potentials more positive than -0.50 V are rich in Se, alternatively films rich in Cd are obtained at potentials more negative than -0.70 V. The Se/Cd ratio of CdSe layers deposited at -0.69 V approach to 1.1, but the content of Se in the deposits increases with increasing H_2SeO_3 concentration. The results showed that the electrodeposition of CdSe follows two different mechanisms corresponding to different deposition conditions. Modification of stoichiometry in CdSe films was also discussed.