Investigating the Infrared Absorption and Optoelectronic Properties of Mn-Doped MoSe2 ML by Adsorption of NOx Gas Molecules

This article uses the first principle calculations, to investigate the electronic (and optical) attributes of NOx-adsorbed gas molecules. To begin, the electronic properties demonstrate the NOx molecules’ effect on the Mn-doped MoSe2 monolayer (ML) in terms of adsorption energy [
${E}_{{({\mathrm {ads}}{)}}}$
], charge transfer (
${Q}_{\text {T}}{)}$
, sensitivity (
$\eta {)}$
, and total density of states (TDOS). Second, the shift in the absorption spectrum (
$\alpha {)}$
of NOx gas molecules adsorbed on the Mn-doped MoSe2 ML demonstrates the optical property. In addition, the adsorption of NO2 gas on the Mn-doped MoSe2 ML exhibits improved interaction, with the highest adsorption energy of −4.01 eV and a charge transfer of
$- 0.06{e}$
, respectively. Later, the increased interaction is justified by the TDOS behavior, which exhibits an increase in impurities near the Fermi level in comparison with NO and
$\text{N}_{{2}}\text{O}$
gas molecules. In addition, the activated Mn atom has a higher sensitivity to the NO2 gas molecule, measuring 56.24%. Finally, the NO2 gas molecule is more amenable to infrared (IR) detection than the Mn-doped MoSe2 ML, as the absorption spectrum shifts to the IR region. As a result, the NOx gas-adsorbed Mn-doped MoSe2 ML is well suited for IR photodetector applications due to its high-IR light absorption molecules.