电容测量研究铬表面氧化膜的半导体性能  

The Semiconducting Properties of Oxide Films Formed on Chromium Studied by Capacitance Measurement

作　　者：孔德生[1] 李亮[2] 

机构地区：[1]曲阜师范大学化学系,曲阜273165 [2]山东大学化学系,济南250100

出　　处：《物理化学学报》2004年第6期631-636,共6页Acta Physico-Chimica Sinica

摘　　要：利用电容测量技术,基于Mott-Sckottky分析,研究了在0.5 mol·L-1H2SO4溶液中铬表面氧化膜的半导体性质,以及膜形成条件的影响.结果表明,铬在钝化电位区内所形成的表面氧化膜具有p-型半导体特性,膜的厚度约(1.2±0.3)nm.膜的阻抗响应表现出低频弥散行为,可以用介电弛豫普适定律来描述.膜的掺杂浓度NA随成膜电位及极化时间的延长而增大,溶液pH值则通过改变膜的表面电荷而影响膜的平带电位EFB。The semiconducting properties of the oxide film formed on chromium were studied by capacitance measurement and the Mott-Schottky analysis. It is shown that the oxide films formed on chromium within the passive potential region in 0.5 mol . L-1 H2SO4 Solution, the thickness of which is about 1.2 +/- 0.3 nm, behavior like a p-type semiconductor. The impedance response of the film showed a low-frequency dispersion, which can be accounted for by dielectric relaxation with complex capacitance. The effects of the film-formation potential, the polarization time, and the solution pH on the semiconductive parameters of acceptor density (N-A) and flatband potential (E-FB) were investigated. The increase of N-A corresponds to the increase of the hydration degree of the oxide\ films. The linear relationship with a slope of similar to59 mV/pH unit between E-FB and solution pH was observed.

关 键 词：铬 钝化膜 电容测量 受主浓度 平带电位 

分 类 号：O649[理学—物理化学]