Structural, electronic, and gas sensing properties of nanoporous based armchair silicene Nanoribbon: A first principles study

Abstract

The growing concern over toxic volatile organic compounds (VOCs), such as methanol and ethanol, which pose health and environmental risks, highlights the need for advanced gas sensors with high sensitivity, rapid response, and quick recovery. Specifically, well-defined, nanoporous structures are crucial for improving sensor sensitivity and selectivity. This article uses first-principles calculations based on density functional theory (DFT) to study the structural, electronic, and gas-sensing properties of one-dimensional nanoporous armchair silicene nanoribbon (ASiNR) and fluorine-functionalized nanoporous ASiNR (F-ASiNR) devices. We have created various point defects, including monovacant (MV), divacant (DV), and trivacant (TV), by selectively removing silicon atoms from the structure. To achieve this, we identified optimal adsorption sites, adsorption energies, interaction distances, and work function values. Additionally, current-voltage analysis confirms that nanoporous ASiNR sensors are highly sensitive, with the TV configuration showing the highest ethanol response of 433 % and excellent selectivity for ethanol over other sensor types. Furthermore, we calculated recovery times under visible light at 300 K, which varied considerably, with the TV sensor exhibiting the shortest recovery times of 2 ms and 1.36 ms for methanol and ethanol, respectively. Our results demonstrate that the proposed nanoporous ASiNR sensors are promising for detecting toxic VOCs and have strong potential for real-world applications in environmental monitoring and safety.