RETRACTED: Theoretical investigation of gas sensing and adsorption based on transition metal (Cu, Co) embedded Se-vacancy defective WSe2 monolayers

Abstract

Abstract In this work, we performed density functional theory calculations to explore the structural, magnetic, and electronic properties of transition metal (Cu, Co) embedded WSe2 monolayers. Both Cu- and Co-embedded WSe2 monolayers are thermodynamically stable. Our results suggested that Cu-embedded monolayers are more stable than the Co-embedded ones. Subsequently, the adsorptions of CO, CO2, NH3, NO, N2O, NO2 and O3 gas molecules on the Cu-embedded WSe2 systems were systematically examined to evaluate their potential for application in gas sensor devices. In the case of Co-embedded WSe2, the magnetic moment is 0.88 μB, while the Cu-embedded system shows a total magnetic moment of 0.82 μB. Thus, we found that the magnetic properties of the WSe2 monolayers are tuned through doping Co and Cu atoms. Our results also indicated that the adsorption performance of WSe2 towards CO detection was slightly improved by applying electric field. The projected density of states of the gas molecules and Cu atoms were also calculated, which indicate the formation of chemical bonds via overlapping electrons of the embedded Cu atom and gas molecules. Our findings are technically important for building gas sensor devices based on transition metal embedded WSe2 monolayers.