Structural and electronic properties of semi-buckled phase of III4–V4 monolayers

Abstract

A new phase of III 4 –V 4 binary monolayers which is non-planar is presented. This new phase which has a particular semi-buckling pattern, is more stable compared to the recently reported planar and III 2 –V 2 ones. In this structure, group-III atoms are located in a hypothetical middling plane while group-V ones are buckling meanderingly around the mentioned plane. Except for B 4 Sb 4 and B 4 Bi 4 , all considered binary compounds in this structure exhibit a direct bandgap at Γ -point. The obtained bandgaps are modified by the B3LYP functional leading to the higher values. Interestingly, the obtained bandgaps for a couple of compounds closely match the solar peak making them a fascinating candidate for the solar applications. The relative and dynamic stability analysis of the compounds are also presented. Since nanoflakes are extremely attractive for the application regarding catalysts and solar energy, here, the energy gap and photocatalytic characteristics for different compositions of ξ -structure III 4 –V 4 nanoflakes are also investigated. Furthermore, their nanoflakes with different sizes are also studied due to their potential applications including two-dimensional photocatalyst . In this regard, the variation of the nanoflake energy gap with respect to its corresponding dimensions is also presented. • A new phase of III-V binary materials which is non-planar and more stable is reported. • A particular semi-buckling pattern which is here called ξ -structure, is observed in this new isomer. • A direct bandgap is observed at Γ -point. • The bandgap is modified by B3LYP functional leading to the higher values. • The modified bandgaps are close to the solar peak.