Ammonia Sensing Performance of a GaN-Based Semiconductor Diode with a Solution-Processed Pt/GaO_x Schottky Contact

Solution processes, including electroless plating and hydrogen peroxide treatment, are employed to fabricate platinum/gallium oxide (Pt/GaOx) Schottky contact on GaN surfaces in this study. Surface morphology and electric characteristics of the resultant diode device are studied. In terms of the sensing properties toward the ammonia in air, this device shows a low operating temperature of 423 K, a wide detection range, and a low detection limit of 0.4 ppm. Furthermore, compared to other semiconductor sensors prepared by high-temperature methods, this device demonstrates a higher sensing speed as well as a greater sensing response of 678.4 in a 1000 ppm ammonia/air ambience; such results can be interpreted due to its robust Schottky contact. Based on the advantages of low-power consumption, excellent sensing performance, and good reliability, the solution-processed Pt/GaOx/GaN device presented in this study is a promising route for ammonia sensing applications.