Type-1 Pentagonal Tiling Realized in 2D Penta-SrP₂ Sheet

Abstract

According to the systematic classification of pentagon-based two-dimensional (2D) materials [Phys. Rep. 2022, 964, 1], only type-2 and type-4 out of the 15 pentagonal tiling patterns have been realized in 2D materials so far. Here, we propose the first stable pentagon-based 2D material characterized by the type-1 pentagonal tiling pattern named penta-SrP 2 . We find that penta-SrP 2 is not only thermally and mechanically stable but also dynamically stable when the temperature is above 200 K derived from the calculations by taking both phonon renormalization and thermal expansion into consideration. Moreover, the penta-SrP 2 sheet is semiconducting with an indirect band gap of 0.96 eV. These findings expand the family of pentagonbased 2D materials in morphology and provide a new perspective to explore the dynamical stability of high-temperature phases.

Computational Investigation on Pentagonal Monolayer HgO2 with Ultrahigh Anisotropic Carrier Mobility and Low Gibbs Free Energy for Photocatalytic Water Splitting

“…Although many 2D photocatalysts have been reported, most of them consist of regular triangles, squares, and hexagons, whereas pentagons are scarce as building blocks of the 2D materials. − The concept of pentagonal 2D materials can date back to the penta-graphene, a novel 2D carbon allotrope consisting of only pentagonal carbon rings in P 42 1 m symmetry within a tetragonal lattice . Beyond the penta-graphene, numerous pentagonal 2D materials have been predicted theoretically, including the pentagon-based unitary silicene and germanene, binary GeP 2 , B 2 N 4 (B 3 N 3 ), B 2 C, X 2 N 4 (X = Ni, Pd, or Pt), P 2 X (X = C and Si), SiX 2 (X = C, N, and P), SrP 2 , X 2 C (X = P, As, and Sb), PdX 2 (X = S, Se, and Te), , and ternary BCN, PdPX (X = S, Se, and Te), PdSSe, BNSi, and BCX (X = P, As, and Sb) . Encouragingly, the pentagonal 2D materials PdSe 2 , , PdS 2 , , NiN 2 , PdPS, and PdPSe , have been experimentally synthesized.…”