Schottky-diode hydrogen sensor based on InGaN/GaN multiple quantum wells

A Schottky-diode hydrogen sensor based on InGaN/GaN multiple quantum wells was fabricated. Its hydrogen-sensing properties (e.g., current-voltage characteristics, barrier-height variation, and response) and its hydrogen adsorption properties (e.g., hydrogen reaction kinetics, transient behavior, response time, and activation energy) were studied over a wide range of temperature or H-2 concentration. Results showed that the device is sensitive to hydrogen ambient even at high temperature (response is 0.11 at 300 degrees C in 810 ppm H-2). According to the kinetic adsorption analysis, the activation energy of the sensor is 4.9 kcal/mol. Moreover, the sensor could perform rapid hydrogen detection at high temperature (response time is 25.1 s at 400 degrees C in 800 ppm H-2). Therefore, the sensor is a useful device for hydrogen-sensing applications, especially at high temperature. (C) 2014 American Vacuum Society.