Simulation of silicene-based photosensor for carbon-based gas molecules

This study simulates a silicene-based photosensor designed for the detection of carbon-based gaseous molecules, such as carbon monoxide (CO), carbon dioxide (CO₂), and methane (CH₄). Using an armchair-edge silicene nanoribbon as the active region of this sensor, we investigated the sensitivity, and selectivity in dark and light conditions at different wavelengths. In the dark condition, the smallest current change of sensors was related to the presence of CH₄. Under illuminated conditions, the sensor sensitivity to CO, CO₂, and CH₄ increased to 2.9, 9.7, and 2.28, respectively, compared to dark conditions. A similar pattern was observed in selectivity, with more pronounced changes in the selectivity of carbon dioxide over methane under illuminated conditions compared to dark conditions. This research confirmed that illumination significantly enhances both the sensitivity and selectivity. Furthermore, it was noted that the recovery time for CH₄ and CO₂ sensing is significantly shorter than that for CO gas.