Phonon-mediated superconductivity in borophenes

We use first-principles calculations to systematically investigate electronic, vibrational, and superconducting properties in borophenes (boron monolayer sheets). Remarkably, superconducting transition temperature Tc is a V-like function of hexagon hole density and has a similar tendency to the variations of the total energy and density of states at the Fermi level, which shows that the larger density of states at the Fermi level corresponds to the higher Tc. In consideration of substrate, the Ag(111) surfaces weaken the superconductivity in borophenes, which results in Tcμ*=0.1 of about 5.2 K in the buckled triangular sheet. As synthesis of borophenes was reported, superconducting boron sheets are feasible.