DocumentCode :
1491242
Title :
Ammonia Sensing Properties of a Pt/AlGaN/GaN Schottky Diode
Author :
Chen, Tai-You ; Chen, Huey-Ing ; Liu, Yi-Jung ; Huang, Chien-Chang ; Hsu, Chi-Shiang ; Chang, Chung-Fu ; Liu, Wen-Chau
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
Volume :
58
Issue :
5
fYear :
2011
fDate :
5/1/2011 12:00:00 AM
Firstpage :
1541
Lastpage :
1547
Abstract :
An interesting Pt/AlGaN/GaN Schottky-type ammonia gas sensor is fabricated and studied. Both the steady-and transient-state behaviors of ammonia adsorption reactions are investigated. At 150°C, significant ammonia detection is observed under a low ammonia concentration of 35-ppm NH3/air. Moreover, a high ammonia sensing response of 18300% and the large Schottky barrier variation ratio A.φbb, air of 13.8% are observed upon exposure to a 1% NH3/air gas at 150°C. The presence of dipoles at the metal-semiconductor interface leads to a lowering effect of Schottky barrier height and a larger current. In addition, based on thermodynamics, in contrast with a hydrogen adsorption reaction, the ammonia adsorption reaction is an endothermic reaction. Consequently, the studied NH3 sensor structure provides the promise to integrate high-performance AlGaN/ GaN-based optoelectronic and microwave devices on a single chip.
Keywords :
Schottky diodes; adsorption; ammonia; gas sensors; thermodynamics; NH3 sensor structure; Pt-AlGaN-GaN; Schottky barrier height; Schottky barrier variation ratio; Schottky diode; Schottky-type ammonia gas sensor; ammonia adsorption reaction; ammonia detection; ammonia sensing properties; endothermic reaction; high-performance AlGaN/GaN-based optoelectronic devices; hydrogen adsorption reaction; metal-semiconductor interface; microwave devices; steady-state behavior; thermodynamics; transient-state behavior; Aluminum gallium nitride; Gallium nitride; Gases; Schottky barriers; Schottky diodes; Temperature sensors; AlGaN; Schottky diode; ammonia; sensor;
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/TED.2011.2115245
Filename :
5746515
Link To Document :
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