The Application of Liquid Junctions for Characterization of Semiconductor Materials

Abstract

In this study, liquid junctions were used to characterize silicon and silicon subjected to various reactive ion etching (RIE); surface optimization of CuInSe{dollar}\sb2{dollar}; and photo-modification of InSe. Impedance spectroscopy and modulation spectroscopies such as electrolyte electroreflectance (EER), photoreflectance (PR), and photoreflectance in the presence of electrolyte (EPR) were the major methodologies that were used for investigating the dielectric properties of the semiconductors and their interface with the ambients. It was shown that the above experimental techniques provide information about the flat-band potential, doping density, Fermi level pinning, the density and distribution of surface states, energy gap and broadening parameter related to the lifetime of majority carriers, etc. The effective medium analysis of the frequency dispersion of the impedance provides the information on the microstructure of the composite at the interface. The analysis of the constant phase angle (CPA) elements reveals the origin of disorder such as diffusion of minority carriers. The change of the line shape of the modulation spectrum provides a sensitive probe for analyzing the tensile strain, the quality of the crystal, etc. Both techniques can be complementary and cross-checked, which comprise a versatile system of characterization for the dielectric properties of semiconducting materials