Electric-field-controlled memory effect in heterostructures for gas sensors

A capacitive gas sensor has been created on the basis of an n-SnO2/SiO2/p-S i heterostructure with two successive oxide layers. The presence of polar C 2H5OH, NH3, and H2O gas molecules in air leads to a significant increase in the capacitance of the structure at room temperature. An important feature of the adsorption process is a memory effect, which is confined to the pos sibility of maintaining the capacitance value after removal of the active c omponent from the gas mixture. The possibility of quenching the accumulated useful signal by electric-field pulses has been realized for the first tim e as applied to gas sensors. (C) 1999 American Institute of Physics. [S1063 -7850(99)02006-6].