학술논문
Pt-AlGaN/GaN Hydrogen Sensor With Water-Blocking PMMA Layer
Document Type
Periodical
Author
Source
IEEE Electron Device Letters IEEE Electron Device Lett. Electron Device Letters, IEEE. 38(5):657-660 May, 2017
Subject
Language
ISSN
0741-3106
1558-0563
1558-0563
Abstract
One of the biggest issues with GaN-based hydrogen sensors is their sensitivity to humidity in the ambient. We demonstrate that encapsulation of Pt-AlGaN/GaN Schottky diode with poly(methyl methacrylate) (PMMA) provides effective mitigation of the effects of water. Without PMMA encapsulation, the absolute current signal for detection of 500 ppm of H 2 was decreased by a factor of 8 in the presence of water. By sharp contrast, encapsulated diodes show no decrease in response in the presence of water. The relative current changes are of the order $2.8 \times 10^{5}$ % when 500 ppm H 2 is introduced to the surface of bare or PMMA encapsulated diodes in the absence of water or to encapsulated diode in the presence of water. Detection limits of ~ 100 ppm H 2 (0.01% by volume) were obtained with standard forward bias detection mode at 1.3 V.