Hydrogen sensing performance of a GaN-based Schottky diode with an H2O2 treatment and electroless plating approach

Abstract

A new electroless plating (EP)-Pd/GaOx/GaN Schottky diode-type hydrogen sensor is fabricated and comprehensively studied herein. The GaOx dielectric is formed as a result of a proper H2O2 treatment on the GaN surface. In addition, a 20-period sensitization/activation process and an appropriate EP approach of the Pd catalytic layer are employed to facilitate a high-performance metal-semiconductor (M-S) Schottky contact. Experimentally, an extremely high hydrogen sensing response of 5.5 × 106 (under 1% H2/air gas) and a relatively low detection limit of 5 ppm H2/air are obtained at 300 K. The corresponding response and recovery times are 22 s and 21 s at 300 K, respectively. A new data transmission algorithm based on the Kalman algorithm is also proposed in this work. According to the simulation results, the data transmission volume can be reduced by 90%. The average recovery error rate is less than 0.38%. Furthermore, our developed reduced redundancy method can pre-warn the user of sensor failure. Based on the advantages mentioned above, therefore, the studied device is promising for high-performance hydrogen sensing and Internet of Things (IoT) applications.