Highly sensitive and selective sensing properties of modified green phosphorene monolayers towards SF₆ decomposition gases

Gas sensing properties of pristine, defective and heteroatom substituted green phosphorene (GP) monolayers towards SF₆ components such as H₂S, SO₂, SO₂F₂, SOF₂ are investigated by using van der Waals corrected density function theory calculations. The adsorptions of H₂S and SOF₂ on pristine GP are found to be exothermic with weak binding energies (E_b) of-0.065 and -0.017 eV respectively, whereas the interactions of SO₂ and SO₂F₂ are endothermic. We found that various vacancy defects and heteroatom substitutions enhance the E_b values of H₂S, SO₂, SO₂F₂ and SOF₂ to -0.84, -1.04, -0.40and -0.73eV, respectively which are within desired range for efficient gas sensing applications. Presence of selected substituents (Al, B, C, S, Si) and vacancy defects result into measurable variations in electronic properties of GP upon the exposure of sulphur containing gases. We found that B- and S-doped GP systems show selectivity towards H₂S and SO₂, with E_b values of -0.57eV for H₂S and -1.03eV for SO₂. We believe that modified GP has potential to be used as excellent sensing material towards SF₆ decomposition gases.