Ga-doped AlN monolayer nano-sheets as promising materials for environmental sensing applications

Abstract

Toxic gases such as NO, CO, and SO can cause severe environmental problems. Therefore, research efforts on designing sensors for these gases are imperative. In this study, we have used first-principles calculations to unveil the atomic configurations, adsorption properties, electronic structures, and optical characteristics of these poisonous gases on Ga-doped AlN monolayer nanosheets from a physical perspective. Our findings reveal that the configurations, band structure, adsorption energy, and sensitivity of the nanosheets are significantly affected by the dopant (Ga atom). A physosorption is suggested for CO and NO adsoption system while a chemisorption is characterised for SO system on the Ga-site, indicating their potential as filtration and sensing materials for NO, CO, and SO gases. NO and CO systems are found to show similar optical properties, with absorption peaks in the ultraviolet (UV) region. The refractive index values for NO and CO adsorbants are 1.3 and 3.56 for SO adsorbant on Ga-site, with a slight increase in the visible area. These insights can aid in developing new AlN monolayer-based materials for environmental and sustainability applications.