Electrical behavior of free-standing porous silicon layers

• Published in: Physica. B, Condensed matter Condensed matter, 2009-06, Vol.404 (12), p.1638-1642
• Main Authors: Bazrafkan, I., Dariani, R.S.
• Format: Article
• Language: English
• Subjects: Activation energy; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electrical behavior; Electrochemical anodization; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Exact sciences and technology; Free-standing porous silicon; Physics; Rectification; Surface resistivity
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2009.01.040

The electrical behavior of porous silicon (PS) layers has been investigated on one side of p-type silicon with various anodization currents and electrolytes. The two contact I– V characteristic is assigned by the metal/porous silicon rectifying interface, whereas, by using the van der Pauw technique, a nonlinear dependence of the current vs voltage was found. By using Dimethylformamide (DMF) in electrolyte, regular structures and columns were formed and porosity increased. Our results showed that by using DMF, surface resistivity of PS samples increased and became double for free-standing porous silicon (FPS). The reason could be due to increasing surface area and adsorbing some more gas molecules. Activation energy of PS samples was also increased from 0.31 to 0.34 eV and became 0.35 eV for FPS. The changes induced by storage are attributed to the oxidation process of the internal surface of free-standing porous silicon layers.