Penta fever going on: conductive Penta-BCN4 with negative differential resistance (NDR)

Pentagonal 2D structures, surpassing conventional hexagonal sheets, are gaining increasing attention due to their exceptional properties and diverse applications. In this study, we investigate penta-BCN4, a ternary monolayer 2D penta structure with intrinsically exceptional properties. Using Density Functional Theory calculations, we found that penta-BCN4 is a conductive material with mechanical, thermal, and dynamic stability. Penta-BCN4 exhibits a high Young’s modulus and a small Poisson ratio, which are isotropic in different directions. In contrast, penta-BCN, which has been previously studied, is mechanically anisotropic. We also discovered that one of the most intriguing properties of penta-BCN4's band structure is the phenomenon of negative differential resistance (NDR). To assess NDR more precisely, we computed the transport in the direction of the N-N bond in addition to the throughput in the direction of the lattice vector (a). The intrinsic NDR of the penta-BCN4 monolayer, combined with its vanishing band gap, makes this material appealing for technological applications, as B, C, and N are abundant resources, light in mass, and environmentally safe. This research expands the possibilities of monolayer 2D penta structures into new avenues.