Title :
On an Ammonia Gas Sensor Based on a Pt/AlGaN Heterostructure Field-Effect Transistor
Author :
Chen, Tai-You ; Chen, Huey-Ing ; Hsu, Chi-Shiang ; Huang, Chien-Chang ; Chang, Chung-Fu ; Chou, Po-Cheng ; Liu, Wen-Chau
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
fDate :
4/1/2012 12:00:00 AM
Abstract :
A new and interesting Pt/AlGaN heterostructure field-effect transistor (HFET)-based ammonia gas sensor is fabricated and investigated. The related ammonia-sensing mechanisms, including direct dissociation of ammonia gas and triple-point model, are presented. Experimentally, the maximum transconductance variation Δgm and threshold voltage variation ΔVth are 16.63 mS/mm and 318.1 mV, respectively, upon exposing to a 10 000-ppm NH3/air gas. In addition, the maximum sensing response and rectification ratio of 113.4 and 2.1 × 103, respectively, are obtained when 10 000- and 35-ppm NH3/air gases are introduced. Therefore, the studied Pt/AlGaN HFET shows the promise for ammonia-gas-sensing applications.
Keywords :
III-V semiconductors; aluminium compounds; field effect transistors; gallium compounds; gas sensors; organic compounds; platinum; wide band gap semiconductors; HFET-based ammonia gas sensor; Pt-AlGaN; ammonia gas model; heterostructure field-effect transistor; triple-point model; voltage 318.1 mV; Aluminum gallium nitride; Gallium nitride; Gases; HEMTs; Logic gates; MODFETs; Sensors; AlGaN; ammonia; heterostructure field-effect transistor (HFET); sensor;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2012.2184832
