ANALYSIS OF THE TIME-DEPENDENCE OF INTERFACIAL POTENTIALS AT ION-CONDUCTING MEMBRANES COUPLED TO FIELD-EFFECT DEVICES

The time dependence of interfacial potentials is analysed approximatel y in terms of the space charge polarization and the diffusion within t he membrane for ion-conducting thin films (less than or equal to 100 n m) used in field effect-based sensors. Results are experimentally veri fied at aluminosilicate thin films fabricated by ion implantation. The polarization leads to an initial transient and a potential displaceme nt by about 52-59 mV per 1 V polarizing voltage. Bulk membrane diffusi on is characterized by a diffusion coefficient for sodium ions of 5 x 10(13)-7 X 10(-13) cm(2) s(-1).