Electrical characterization and hydrogen gas sensing properties of a n-ZnO∕p-SiC Pt-gate metal semiconductor field effect transistor

Abstract

A new hydrogen gas sensitive $n\text{-}\mathrm{Zn}\mathrm{O}∕p\text{-}\mathrm{Si}\mathrm{C}$ Pt-gate metal semiconductor field effect transistor (MESFET) is reported. The observed current-voltage curves for the source to drain region indicate that this MESFET operates in enhancement mode. A change in gate potential, due to different ambient atmospheres caused a change in the width of the depletion region, hence modulating the current in the $n$ channel (ZnO layer). The ${\mathrm{H}}_2$ gas sensing mechanism of the presented MESFET structure is discussed using energy band diagrams.