Arsenene nanoribbons for sensing NH3 and PH3 gas molecules - A first-principles perspective

Using first-principles calculation, the electronic and adsorption characteristics of ammonia (NH3) and phosphine (PH3) gas molecules on hydrogenated armchair arsenene (arm-HAs) and hydrogenated zigzag arsenene nanoribbon (zig-HAs) are studied. Initially, the stability of HAs nanoribbons are examined with formation energy. The band gap of armchair HAs is calculated to be 1.39 eV and for zigzag HAs it is noticed to be 1.03 eV. It is found in the present framework that the arm and zig-HAs nanoribbons can be employed for recognizing toxic gas molecules like NH3 and PH3. The density of states (DOS) spectrum and energy band structure ascertains the transfer of electrons between the toxic gas molecules and arm/zig-HAs nanoribbon. In addition, the adsorption behavior is substantiated from the energy band gap, electron density, adsorption energy and Bader charge transfer of the solitary and toxic gas molecules adsorbed arm/zig-HAs nanoribbon. Hence, the report reveals that both arm and zig-HAs nanoribbons can be utilized for detecting the poisonous gas molecules NH3 and PH3, which shows the variation in the resistance upon adsorption.