Study on the Electronic Properties of th-A1N Adsorption by Gases

The novel proposed two-dimensional tetrahex aluminum nitride (th-AIN) has the advantages of wide bandgap, indirect transition, high-temperature resistance, high stability, and high electron mobility. Because low dimensional materials with large specific surface areas are sensitive to the material surface, the electron adsorption properties of background air gases molecules O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>, N2, CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{H}_{2}\mathrm{O}$</tex> and polluted gases molecules SO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>, NO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>, CH<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf>, CO, and NO on th-AIN surface were studied, and the sensitivity and selectivity of material for gases were discussed using bonding, calculation of adsorption energy, energy band structure and density of states curve. <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$N2, \mathrm{H}_{2}\mathrm{O}, CO2$</tex> and CH4 adsorption of th-AIN is physical adsorption and th-AIN with no significant change in band structure is not sensitive to it. O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>, CO, NO, NO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> and SO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> adsorption of th-AIN is chemical adsorption, that causes the bandgap to decrease significantly, and th-AIN with a significant change in band structure has a certain degree of sensitivity to it. Meanwhile, O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> adsorption of th-AIN will cause the bandgap to decrease significantly, transforming the indirect-direct transition mode. Thus, th-AIN must isolate oxygen when used as the gas-sensing material. <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{O}_{2}/\text{NO}/\text{NO}_{2}/\text{SO}_{2}+\text{AlN}$</tex> adsorption system all exhibit magnetism, with varying magnetic moments of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.68 \mu \mathrm{B}\sim 1.52\mu \mathrm{B}$</tex>. Some results of this study provide theoretical guidance for future design and synthesis of th-AIN gas sensing material.