Humidity sensor element based on porous silicon – reduced graphene oxide sandwich-like structures

Abstract

In this study, the field-effect transistor (FET) based on porous silicon (PS) – reduced graphene oxide (rGO) sandwich-like structure is suggested as a sensitive element of the humidity sensor. It is shown that the position of the charge neutrality point (Dirac point) and the ratio between the hole and electron branches of the resistance profile of the PS–rGO-based FET depend significantly on the relative humidity. An increase in air humidity causes a decrease in the electrical resistance and an increase in the capacity of the obtained FET. The sensing ability and dynamic characteristics were analyzed to estimate the sensory properties of the PS–rGO sandwich-like structure. A higher sensitivity of the resistive sensor element than the capacitive has been found. The response time of the obtained sensors to changing relative humidity is about 1 min at room temperature. As a result, the PS–rGO-based FET demonstrates high potential applications in humidity-sensitive devices.