Selective hydrogen detection of Pd/AlGaN/GaN HEMT-type sensors by temperature sweep operation

Abstract

We have demonstrated the selective hydrogen gas detection of Pd/AlGaN/GaN high electron mobility transistors-based hydrogen sensors by the temperature sweep operation. The sensitivity-temperature spectra of the Pd/AlGaN/GaN HEMT hydrogen sensors in the range of 30°C to 350°C were measured in hydrogen, methane and propane with various concentrations of diluted with nitrogen. It is found that the different gases have the characteristic sensitivitytemperature spectra with the different peak positions, which is due to the decomposition temperature of each gas. The maximum sensitivities to hydrogen and propane are obtained at about 230°C and 310°C, respectively. The temperature sweep detection is very useful technique for the selective gas detection for the Pd/AlGaN/GaN HEMT-based gas sensors.

A comprehensive review of gallium nitride (GaN)-based gas sensors and their dynamic responses

“…2(d)). 85 They found that each gas had a characteristic spectrum of sensitivity to temperature at different peak positions owing to their different decomposition temperatures. When the gas concentration was 1000 ppm, the highest response sensitivities of H 2 , CH 4 , and C 3 H 8 were all around 0.78, but the optimized temperatures at their maximum sensitivity were 230 °C, 350 °C, and 310 °C, respectively.…”