摘要
应用自装微机联用恒电位系统研究了在玻璃碳或铁电极上Te、CdTe、HgCdTe的电沉积及其电结晶成核机理。结果表明,在酸性溶液中,HTeO_2^+的阴极还原符合4电子还原机理,其电结晶生长表现为由HTeO_2^+扩散控制的三维瞬时成核机理;CdTe沉积层的形成是亚碲酸还原的延续,其电结晶成核机理因电位阶跃值、沉积温度及溶液pH值的改变而由HTeO_2^+扩散控制的三维瞬时成核转变为二维瞬时成核机理;对HgCdTe,其电沉积过程的动力学步骤可设想为: Hg^(2+)+2e—→Hg,HTeO_2^++3H^++4e—→Te+2H_2O xHg+Te—→Hg_2Te,Hg_2Te+(1—x)Cd^(2+)+2(1—x)e—→Hg_2Cd_(1-2)Te 相关的结晶生长除受各种实验因素影响外,还与CdTe的成核过程有关。在本文实验条件下,大体遵循二维瞬时成核机理。
The electrodeposition and nucleation mechanism of Te, CdTe and HgCdTe at glassy-carbon or titanium electrode were investigated. The results show that; (1)The cathodic reduction of HTeOjf in acidic solution obeys the four-electron reduction mechanism. The electrocrystallization of Te at Ti electrode is followed by three-dimensional instantaneous nucleation mechanism controlled by diffusion of HTeO+2 ions. (2)CdTe is electrodeposited according to the reduction of tellurous acid followed by the electroreduction of Cd2+ and Te. Howerer, the electrocrystallization of CdTe is relatively complicated. According to the variation of step potential, temperature and pH of the solution, the electro-crystallization of CdTe at Ti electrode is transformed from three-dimensional instantaneous nucleation controlled by diffusion to two-dimensional instantaneous nucleation mechanism. (3)The mechanism electrodeposition of HgCdTe can be considered as following:And its electrocrystallization growth depends on the nucleation of CdTe, and it seems to follow the two-dimensional instantaneous nucleation mechanism under our experimental conditions.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1993年第5期675-680,共6页
Chemical Journal of Chinese Universities
基金
国家自然科学基金
关键词
电沉积
膜
电结晶成核
碲
碲化镉
Te, CdTe, HgCdTe, Electrodeposited films, Electrocrystallizatlon nucleation
