Fabrication and the Interlayer Coupling Effect of Twisted Stacked Black Phosphorus for Optical Applications

Abstract

With a new polycarbonate-film-based dry transfer method, we successfully fabricated twisted stacked black phosphorus. Optical characterization showed the overlapping area had special optical response, and high-frequency Raman spectroscopy showed unexpected blue shifts in Ag 1 and Ag 2 modes. Density functional theory (DFT) calculations confirmed these blue shifts in twisted bilayer black phosphorus, and revealed significant interlayer coupling effects. Charge distribution calculations indicated other interactions beyond van der Waals force may exist in twisted bilayer black phosphorus. This finding may cast some insight on phonon modulation effect and give some potential applications such as optical filters and infrared photodetectors.

Strain-engineered widely tunable perfect absorption angle in black phosphorus from first principles

“…From the magnetic field component, we can use Eqs. (6) to easily deduce the electric field components. For BP region, the general form of the E field is a linear combination of waves with wave vectors given in Eq.…”

“…II, the E x (z), E y (z) components of the electric field can be obtained by substituting the H y (z) field into the original Maxwell's equations, i.e., Eqs. (6). For a sufficiently large BP sample, the local permittivity at a certain location with a certain strain (according to the above linear model) can be approximately calculated with DFT using the bulk black phosphorus unit cell.…”

“…Bulk black phosphorus (BP) is an anisotropic semiconductor with two types of chemical bonding. Along two principal crystal directions, the phosphorus atoms form covalent bonds with a puckered honeycomb arrangement, whereas in the third direction atoms interact relatively weakly through van der Waals forces [1][2][3][4][5][6]. The latter bonding results in a layered configuration consisting of two-dimensional phosphorus sheets.…”

“…The latter bonding results in a layered configuration consisting of two-dimensional phosphorus sheets. These weakly interacting two-dimensional layers provide a unique opportunity to create different orderings of two-dimensional layers with extremely low-cost and simple operations, including displacement and twist [5][6][7][8][9][10][11][12][13][14][15][16][17]. The ordering and number of layers, as well as their deformation, can effectively control the electronic properties of BP-based devices.…”

Recent Advances in Twisted Structures of Flatland Materials and Crafting Moiré Superlattices

“…Struck by current development, BP has also been fabricated and simulated for a range of twist angles to unlock the moiré bilayer superlattice, which is a new electronic phenomenon. [ 186–190 ] The stacking arrangements are shown to directly induce direct bandgaps ranging from 0.78 to 1.04 eV, which could be further developed provided the heterostructure with MoS 2 is determined to be an efficient effective solar‐cell material with type‐II heterojunction alignment. [ 191 ] Here, we review the potential contribution of phosphorene, with its anisotropic rectangular lattice, toward developing moiré physics.…”