P2.9.1 Thermodynamic Studies on GaAs-Based Chemical Sensors with a Mixture of Pd and SiO2

Chih Y. Wei, Shih W. Tan, Tzung M. Tsai, Wen S. Lour & Chieh Lo
Thermodynamic sensing properties of GaAs-based hydrogen sensors with a mixture of Pd and SiO2 were investigated by raising ambient temperature. Temperature dependence of the ability of SiO2 to catch hydrogen atoms was addressed to introduce a newly possible sensing mechanism for innovative sensor design. A high sensing current gain over 3000, a detection limit lower than 50 ppm, and a response time shorter than 20 s were obtained from the sensor.