Hydrogen Sensing Characteristics of Pt Schottky Diodes on () and (010) Ga2O3Single Crystals

We investigated the hydrogen sensing characteristics of Pt Schottky diodes on and (010) β- Ga 2 O 3 bulk crystals. The Pt Schottky diodes on β- Ga 2 O 3 wafer exhibited the fast, reversible, and cyclic response upon hydrogen exposure. The maximum value of the relative current change of the Ga 2 O 3 diode sensor was as high as 7.86 × 10 7 (%) at 0.8 V, which is slightly higher than that of the (010) Ga 2 O 3 diode. The hydrogen responses of both β- Ga 2 O 3 diode sensors are believed to result from oxygen and gallium atomic configurations of Ga 2 O 3 surfaces for hydrogen adsorption. The Pt Schottky diodes of Ga 2 O 3 wafers did not show any clear response to other gases, such as N 2 , CO, CO 2 , O 2 , CH 4 , NO 2 , and NH 3 . Our finding suggests that the Pt Schottky diodes on β- Ga 2 O 3 hold great potential for the applications of hydrogen gas sensors with high sensitivity and selectiv…