Phase diagram and superlattice structures of monolayer phosphorus carbide ( PxC1−x )

Abstract

Phase stability and properties of two-dimensional phosphorus carbide, PxC1-x (0 ≤ ≤ 1), are investigated using the first-principles method in combination with cluster expansion and Monte Carlo simulation. Monolayer PxC1-x is found to be a phase separating system which indicates difficulty in fabricating monolayer PxC1-x or crystalline PxC1-x thin films. Nevertheless, a bottom-up design approach is used to determine the stable structures of PxC1-x of various compositions which turn out to be superlattices consisting of alternating carbon and phosphorus nanoribbons along the armchair direction. Results of first-principles calculations indicate that once these structures are produced, they are mechanically and thermodynamically stable. All the ordered structures are predicted to be semiconductors, with band gap ranging from 0.2 to 1.2 eV. In addition, the monolayer PxC1-x are predicted to have high carrier mobility, and high optical absorption in the ultraviolet region which shows a red-shift as the P:C ratio increases.These properties make 2D PxC1-x promising materials for applications in electronics and optoelectronics.

Electrolytic Synthesis of White Phosphorus Is Promoted in Oxide-Deficient Molten Salts

“…Graphite rods were used for all electrodes in a standard 3-electrode analytical setup (working, counter, and reference). Whereas many transition metals readily form metal phosphide alloys, , carbon is highly immiscible with phosphorus; , accordingly, we found graphite to be stable under cathodic conditions, displaying no significant changes in mass nor surface area under any conditions examined in this study. By comparison, the β-alumina membrane of the Na/Na + reference electrode was subject to corrosion upon prolonged exposure to the melt; as a result, it was instead used to calibrate a graphite pseudoreference electrode, the two comprising a quasireference electrode pair (Figure S5).…”

Efficient Electrosynthesis of White Phosphorus from Molten Condensed Phosphate Salts

“…Graphite rods were used for all electrodes in a standard 3-electrode analytical setup (working, counter, and reference). Whereas many transition metals readily form metal phosphide alloys (29,30), carbon is highly immiscible with phosphorus (31,32); accordingly, we found graphite to be stable under cathodic conditions, displaying no significant changes in mass nor surface area under any conditions examined in this study. By comparison, the alumina-body Na/Na + reference electrode was subject to corrosion upon prolonged exposure to the melt, and so it was instead used to calibrate a graphite pseudoreference electrode, the two comprising a quasireference electrode pair (Fig.…”

Electrostatic Gating of Phosphorene Polymorphs

“…In addition, a new family of 2D materials consisting of phosphorus and carbon (phosphorene carbide, (PC)) has been rather recently predicted theoretically. 40 − 43 Interestingly, the experimental realization of 2D PC allotropes was achieved by combining the theoretical predictions and previous experimental observations. 44 These studies demonstrated that various structures in phosphorus carbide can be produced by considering different atomic ratios of P/C.…”

“…The resulting stacks can be characterized into three types: in-plane shifted, in-plane twisted, and hybrids of the former two polymorphs. In addition, a new family of 2D materials consisting of phosphorus and carbon (phosphorene carbide, (PC)) has been rather recently predicted theoretically. − Interestingly, the experimental realization of 2D PC allotropes was achieved by combining the theoretical predictions and previous experimental observations . These studies demonstrated that various structures in phosphorus carbide can be produced by considering different atomic ratios of P/C. − Furthermore, structure, stability and electronic properties of PC monolayers, namely α-, β-, and γ-PC, have been predicted .…”