Modification of the Electrical Properties of Porous Silicon by Adsorption of Ammonia Molecules

Abstract

It was studied electrophysical characteristics of porous silicon (PS) layers formed on single-crystalline silicon substrates with both n-and p-types of conductivity under conditions of adsorption of ammonia molecules. An increase in the conductivity of PS-n-Si structures was observed with increasing ammonia concentration. The adsorption of ammonia was shown to give rise to 'diode-like' current-voltage characteristics of PS-p-Si structures. Spectral characteristics of photovoltage and absorption bands in the infrared spectrum for our structures subjected to ammonia adsorption were studied. We suggested a possible mechanism for the influence of ammonia adsorption on the properties of the PS-silicon structures.