First-principles investigation of armchair boron nitride nanoribbons for sensing PH3 gas molecules

• PH3 molecules are adsorbed on the edges of armchair boron nitride nanoribbons (ABNNR).
• B edge of the ribbon is more energetically favorable than N edge.
• PH3 adsorptions do not cause structural deformation in the geometry of the ABNNR.
• Presence of PH3 significantly affects the electronic properties of ABNNR.

The present work exhibits density functional theory (DFT) based first-principles calculations to explore the sensing properties of bare armchair boron nitride nanoribbons (ABNNR) for PH3 gas molecules. Edges of the ribbon were considered as the sites of possible adsorption with two different configurations i.e. adsorption at one edge and adsorption at both edges of the ribbon. It is revealed that B atoms of the ribbons are more energetically favorable sites for the adsorption of PH3 molecules as compared with N atoms. The adsorption of PH3 affects the electronic properties of nanoribbons. One edge PH3 adsorbed ribbons are metallic whereas in both edges PH3 adsorption, the band gap is decreased than that of bare ribbon. The changes in electronic properties caused by PH3 adsorption are further supported by the current–voltage (I–V) characteristics of the considered configurations. The results show that ABNNR can serve as a potential candidate for PH3 sensing applications.

Transverse view of optimized PH3 adsorbed ABNNR showing the calculated bond lengths and the bond-angles.The PH3 molecule is adsorbed on the edges of ABNNR via P atom. The adsorption of guest PH3 molecules does not cause structural deformation in the nanoribbon. B edge is found more energetically favorable for PH3 adsorption than the N edge.Figure optionsDownload as PowerPoint slide