InP₃ Monolayer as a Promising 2D Sensing Material in SF₆ Insulation Devices

In this letter, we perform a first-principles study on the adsorption performance of the InP₃ monolayer upon three SF₆ decomposed species, including SO₂, SOF₂, and SO₂F₂, to investigate its potential as a resistance-type, optical or field-effect transistor gas sensor. Results indicate that the InP₃ monolayer exhibits strong chemisorption upon SO₂ but weak physisorption upon SO₂F₂. The most admirable adsorption behavior is upon SOF₂, which provides a favorable sensing response (-19.4%) and recovery property (10.4 s) at room temperature as a resistance-type gas sensor. A high response of 180.7% upon SO₂ and a poor one of -1.9% upon SO₂F₂ are also identified, which reveals the feasibility of the InP₃ monolayer as a resistance-type sensor for SO₂ detection with recycle use via a heating technique to clean the surface. Moreover, the InP₃ monolayer is a promising optical sensor for SO₂ detection due to the obvious changes in adsorption peaks within the range of ultraviolet and is a desirable field-effect transistor sensor for selective and sensitive detection of SO₂ and SOF₂ given the evident changes of Q _T and E _g under the applied electric field.