Document Type : Original Article
Authors
1
Department of Electrical, Biomedical and Mechatronics Engineering, Qa .C., Islamic Azad University, Qazvin, Iran
2
Department of Electrical, Biomedical and Mechatronics Engineering, Qa .C., Islamic Azad University, Qazvin, Iran.
3
Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz, Iran.
Abstract
In this paper, the effect of lithium atom doping on the sensing behavior of χ₃ borophene toward CO, NO₂, NH₃, and H₂S gases is investigated and modeled using density functional theory (DFT) and non-equilibrium Green’s function (NEGF) calculations. Band structure and density of states (DOS) analyses revealed that pristine borophene exhibits metallic properties with a high DOS near the Fermi level. Lithium doping significantly increases the DOS, creates new active sites, and enhances charge transfer upon interaction with gases. The modeling results show that lithium dramatically increases the total adsorption energy and transforms the adsorption mechanism of NO₂, NH₃, and H₂S from physisorption to chemisorption, such that the adsorption energy of CO changes from −1.52 eV to −2.21 eV, NO₂ from −1.56 eV to −5.09 eV, NH₃ from −0.17 eV to −3.21 eV, and H₂S from −0.22 eV to −3.16 eV. Furthermore, the current–voltage characteristics indicate that gas adsorption induces significant changes in the electronic conductance of borophene, and the emergence of negative differential resistance (NDR) regions in the curves implies a high tunability of the electronic response. Lithium doping substantially enhances the adsorption capability, charge transfer, and electronic response of borophene, making it a highly efficient, stable, and tunable platform for developing high-sensitivity and selective gas sensors.
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