Effect of humidity on hydrogen sensitivity of Pt-gated AlGaN/GaN high electron mobility transistor based sensors

Abstract

The effects of relative humidity on sensing characteristics of Pt-gated AlGaN/GaN high electron mobility transistor diode based hydrogen sensors were investigated. The absorbed water and oxygen molecules blocked available Pt surface adsorption sites for H2 absorption and reduced the hydrogen sensing sensitivity compared to low humidity conditions. The hydrogen sensing sensitivity decreased proportional to the relative humidity. However, the presence of humidity improved the sensor recovery characteristics after exposure to the hydrogen ambient.