  The allotropes of a new layered material, phosphorus carbide (PC), have been
predicted recently and a few of these predicted structures have already been
successfully fabricated. Herein, by using first-principles calculations we
investigated the effects of rippling a PC monolayer, one of the most stable
modifications of layered PC, under large compressive strains. Similar to
phosphorene, layered PC was found to have the extraordinary ability to bend and
form ripples with large curvatures under a sufficiently large strain applied
along its armchair direction. The band gap size, workfunction, and Young's
modulus of rippled PC monolayer are predicted to be highly tunable by strain
engineering. Moreover, a direct-indirect band gap transition is observed under
the compressive strains in a range from 6 to 11%. Another important feature of
PC monolayer rippled along the armchair direction is the possibility of its
rolling to a PC nanotube (PCNT) under extreme compressive strains. These tubes
of different sizes exhibit high thermal stability, possess a comparably high
Young's modulus, and a well tunable band gap which can vary from 0 to 0.95 eV.
In addition, for both structures, rippled PC and PCNTs, we have explained the
changes in their properties under compressive strain in terms of the
modification of their structural parameters.
