Microstructure, electrical and gas sensing properties of meso-porous silicon and macro-porous silicon

Abstract

Two different kinds of porous silicon (PS) were grown by electrochemical corrosion in a double-tank cell on the surface of single-crystalline P-type silicon. According to their pore sizes, they were denoted as meso-porous silicon (meso-PS) and macro-porous silicon (macro-PS). The surface and cross-section morphologies of the PS were observed by scanning electron microscope (SEM). The surface chemical bonds of the meso-PS and macro-PS were investigated by Fourier transform infrared (FTIR) spectroscopy. The electrical properties of the PS were studied by measuring the I-V characteristics. The gas sensing properties of meso-PS and macro-PS were thoroughly measured at room temperature. Meso-PS has much higher sensitivity, while macro-PS has better response-recovery characteristics. Meso-PS shows better selectivity for NO 2, while macro-PS shows better selectivity for NH 3. © Editorial office of Acta Physico-Chimica Sinica.