Investigation of Sensing Properties of NOx Adsorbed Gas Molecules on Fe-Doped MoSe₂ Monolayer
Neha Mishra, Bramha P. Pandey, Brijesh Kumar, V. K. Tomar, Santosh Kumar
Abstract
In this paper, the authors explore the impact of NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> (NO, NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O) gas molecule’s adsorption on the sensing properties of Fe-doped MoSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> monolayer. Formation and binding energy confirm the electronic stability for pristine and doped monolayers. In terms of electronic parameters of interest, the sensing is adsorption energy, charge transfer, recovery time, the density of states (TDOS), conductivity, and sensitivity. Firstly, the adsorption energy (E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ads</sub> ) is analyzed in the sequence of 1.37, 2.00, 0.07 eV. Secondly, the study of charge transfer is in order of 3.67e, 5.91e, 5.90e. It is observed that charge transfer aligns with the trend of adsorption energy. Third, recovery time as a parameter of reusability of Fe-doped MoSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> monolayer by a detachment of gas molecules is estimated. The N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O gas molecule takes minimum time for separation with a value of 0.15 pico sec. Fourth, adsorbed systems’ density of states (DOS) (NO/Fe-doped MoSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Fe-doped MoSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O/Fe-doped MoSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) accounts for the population of electrons present in different energy levels showing impurities in the Fermi level region. These impurities arouse to asymmetrical nature of the TDOS inducing magnetic domains in it. Fifth, conductivity as an application of modulated bandgap is studied, and NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gives the highest conductivity of 0.49. Lastly, sensitivity as a practical sensing parameter concludes the three adsorbed configurations with a maximum sensing response of 89.69% for NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gas molecules. Therefore, analyzing three NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> gas molecules regarding electronic properties concludes that the Fe-doped MoSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> monolayer more suitably senses NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gas molecules