High-Performance NH₃ Sensors Based on Surface Modification by Plasma and Irradiation at Room Temperature

In this paper, we investigated the sensor characteristics of gas-sensitive sensors with the structure of rGO sprayed onto interdigital electrodes under test conditions of room temperature and 47.2% RH (relative humidity), which were obtained through the surface modification methods of plasma treatment and irradiation treatment. First, we prepared a batch of sensors through experimental procedures and then obtained sensors with good gas-sensitive performance by varying the heating temperature of the sensors and the channel width of the interdigital electrodes. Second, plasma surface modification was utilized to enhance the sensitivity of the sensors. Third, irradiation modification was implemented to improve the sensor performance, including response and recovery times as well as sensitivity. Moreover, the response and recovery curves of the sensors under different NH₃ gas concentrations were measured. It was found that the two surface modification methods, plasma treatment and surface irradiation treatment, have a prominent impact on the improvement of response and recovery times and sensitivity in the sensor. In addition, we tested the selectivity and repeatability of the sensor and found that the sensor was more selective for NH₃ compared to NO₂, and has excellent repeatability. Finally, we fully characterized the material to explore the mechanism.