SiO2 passivation effect on the hydrogen adsorption performance of a Pd/AlGaN-based Schottky diode

Autor: Yaw Wen Kuo, Tzu Pin Chen, Huey-Ing Chen, Tsung-Han Tsai, Wen-Chau Liu, Ching Wen Hung, Li Yang Chen, Kun-Wei Lin, C. Chang, Yi Chun Liu
Rok vydání: 2009
Předmět:
Zdroj: Sensors and Actuators B: Chemical. 136:338-343
ISSN: 0925-4005
DOI: 10.1016/j.snb.2008.12.030
Popis: In this work, the comprehensive study of the hydrogen adsorption effects on the Pd/AlGaN-based MOS Schottky diode with SiO 2 passivation is demonstrated. Hydrogen sensing performance of the proposed device is significantly enhanced with the insertion of SiO 2 layer. The MOS diode exhibits a maximum sensing response value of 3.3 × 10 5 at 70 °C under a 1% H 2 /air gas. Additionally, the operating temperature for the maximum sensing response is decreased from 150 °C to 70 °C with the insertion of SiO 2 layer. Moreover, the lowering of Schottky barrier height is 230 (200) meV for the MOS (MS) diode at room temperature. The hydrogen adsorption effect also largely influence the effective Richardson's constant. Furthermore, the transient-state experiments reveal that the MOS Schottky diode exhibits an activation energy of 14.1 kJ/mol which is lower than the MS Schottky diode (25 kJ/mol). Therefore, hydrogen sensing performance of the AlGaN-based Schottky diode can be significantly enhanced with the SiO 2 passivation on the AlGaN surface.
Databáze: OpenAIRE