A methane sensitive Ni/n-GaN Schottky barrier sensor

In this work, the forward current of Ni/GaN Schottky barrier is found to increase significantly upon Ar, 5%CH/sub 4//90%Ar, 10%CH/sub 4//90%Ar and 15%CH/sub 4//85%Ar ambient. Analysis of the current-voltage characteristics as a function of temperature showed strong correlations Schottky barrier height (SBH) which is related to the work function of Ni and electron affinity of GaN. The resistance of Ni/n-GaN sensor decreased with operating temperatures or concentration of methane were increased. The Ni/ n-GaN samples in Ar ambient exhibited a higher resistance than the CH4 within the temperature range used in this study.