Theoretical prediction of sandwiched two-dimensional phosphide binary compound sheets with tunable bandgaps and anisotropic physical properties

Abstract

Atomic layers of GaP and InP binary compounds with unique anisotropic structural, electronic, and mechanical properties have been predicted from the first principle molecular dynamics simulations. These new members of phosphide binary compounds family stabilize to a sandwiched two-dimensional (2D) crystalline structure with orthorhombic lattices symmetry and high buckling of 2.14 Å-2.46 Å. Their vibration modes are similar to those of phosphorene with six Raman active modes ranging from ~80 cm -1 to 400 cm -1 . The speeds of sound in their phono dispersions reflect anisotropy in their elastic constants, which was further confirmed from their strong directional dependence of Young's moduli and effective nonlinear elastic moduli. They show wide bandgap semiconductor behavior with fundamental bandgaps of 2.89 eV for GaP and 2.59 eV for InP, respectively, even wider than their bulk counterparts. Such bandgaps were found to be tunable under the strains. In particular, a direct-indirect bandgap transition was found under certain strains along zigzag or biaxial orientations, reflecting their promising applications for the strain-induced bandgap engineering in nanoelectronics and photovoltaics. Feasible pathways to realize these novel 2D phosphide compounds were also proposed in this work.

A direct Z-scheme g-C6N6/InP van der Waals heterostructure: a promising photocatalyst for high-efficiency overall water splitting

“…However, their oxidation and reduction capacities are reduced. According to theoretical calculations, an InP monolayer has high stability and might be used as a photocatalyst to produce hydrogen from water [35]. Additionally, monolayer indium phosphide (InP) possesses a direct bandgap value of approximately 1.80 eV [36,37].…”

Anisotropic and Nonlinear Mechanical Properties in Two-dimensional Nanomaterials

“…Quite recently, the 2D sandwiched GaP and InP binary compounds were theoretically predicted by our group [38]. Comparing with the previous predicted lowbuckled Gap and InP sheets [51], the newly predicted sandwiched GaP and InP binary compounds are energetically more stable.…”

“…In this paper, we will present our recent study on the anisotropic and nonlinear mechanical properties of 2D nanomaterials, especially, on graphene, SiC sheet, and recently predicted 2D sandwiched GaP and InP binary materials [38]. We performed a comprehensive computational calculation based on the state-of-the-art quantum mechanics based mothed [39][40][41] and studied the response of mechanical properties to various strains exerted on these 2D nanomaterials.…”

“…The stiffness and the nonlinear elastic moduli in graphene are greatest [42], followed by 2D SiC monolayer [43]. While the 2D III-V binary compounds, e.g., recent predicted sandwiched GaP and InP structures [38] possess significant anisotropic and nonlinear mechanical properties. Especially, their moduli along the zigzag direction are about 3-9 times greater than those along the armchair direction.…”