用复阻抗法研究光照下n-InP/溶液界面的扩散过程

A STUDY OF DIFFUSION PROCESS AT n-InP/SOLUTION INTERFACE UNDER IRRADIATION WITH IMPEDANCE

近年来,一些作者测定了半导体电极的复阻抗,而n-InP的复阻抗至今未见报道。本文测定了n-InP在Fe3+/Fe2+溶液中的复平面图,它在低频区为一直线,应用Randles频谱图,证明其符合混合控制机理,研究了电极电位及光强对频谱图的影响,并用理论模型对实验结果进行了解释。理论部分n型半导体当电极电位负于平带电位时,表面为反型层,则氧化剂阴极还原过程为O+ne→R若反应完全不可逆,则电流密度J符合下列关系式:

In this paper impedance of n-InP in Fe^(3+)/Fe^(2+) solution is determined. The impedance at low frequencies in accord with Randles frequencies spectra figure and the electrode reaction are irreversible. Influences of electrode potential and light intensities are investigated. The results obtained can be explained with a theoretical model derived.