Author/Authors :
Wang، نويسنده , , Yu-Lin and Chu، نويسنده , , B.H. and Chang، نويسنده , , C.Y. and Chen، نويسنده , , K.H. and Zhang، نويسنده , , Y. and Sun، نويسنده , , Q. and Han، نويسنده , , J. and Pearton، نويسنده , , S.J. and Ren، نويسنده , , F.، نويسنده ,
Abstract :
N-polar and Ga-polar GaN grown on c-plane sapphire were used to fabricate platinum deposited Schottky contacts for hydrogen sensing at room temperature. After exposure to hydrogen, Ga-polar GaN Schottky barrier reduced by 3–4 meV, while the N-polar GaN Schottky contacts became fully Ohmic. The N-polar GaN Schottky diodes showed stronger and faster response to 4% hydrogen than that of Ga-polar Schottky diodes. The abrupt current increase from N-polar GaN Schottky exposure to hydrogen was attributed to the high reactivity of the N-face surface termination. The surface termination dominates the sensitivity and response time of the hydrogen sensors made of GaN Schottky diodes.
Keywords :
Ga-face GaN , N-face GaN , Hydrogen sensors , GaN Schottky diodes , N-polar GaN , Ga-polar GaN
