Semiconducting phase in borophene: Role of defect and strain

Boron is an interesting element due to its chemical and structural complexity. Recent synthesis of borophene led scientists to study boron monolayer-based materials for various applications. Using density functional theory calculations, nineteen different phases of boron monolayer (with hexagonal hole densities from 1/32-8/32) are studied to understand their origin of buckling, stability, and planarity. Projected densities of states of various phases of borophene-based systems with defect are plotted into in-plane (s + p_x + p_y) and out-of-plane (p_z) orbitals to understand the role of the σ and π-bands towards their geometry and stability. Interestingly, the λ₅-sheet shows semiconducting properties under uniaxial/biaxial tensile/compressive strains and it shows excellent dynamical, thermal, and mechanical properties and is thus a promising semiconducting phase for electronic devices.