Abstract
We report the electronic, mechanical, and optical properties of the new 1T PdPo2 and PtPo2 pristine monolayers, which display a metallic behavior. In the vicinity of the Fermi level, the contributions to the density of states stem from the pz orbitals of Po and the d-states of Pd (Pt). The 2D structures are dynamically stable, showing positive frequencies, except for insignificant negative values in the neighborhood of the Γ point in PtPo2. The three lowest optical modes are distinguished by non-vibrating Pd and Pt atoms. Positive in-plane elastic constants indicate the systems’ mechanical stability. Compared to other transition metal dichalcogenides (TMDs), the dipolonides are the most malleable. Our new structures are also thermally stable, showing slight distortions of the trigonal environment but no bond breaking or structural destruction up to a 900 K temperature. The absorption coefficients are non-zero at the infrared level for polarized light along the in-plane directions. This feature is absent in other TMDs, due to their semiconducting aspect. The in-plane reflectivities are also high in this regime. Along the direction perpendicular to the plane of the structures, the 1T PtPo2 shows a larger maximum reflectivity in the ultraviolet region. This implies that it can, in principle, be appropriately harnessed to serve as both infrared and ultraviolet shield covers.
•1T-PdPo2 and PtPo2 monolayers are metallic, contrary to other Pd and Pt based dichalcogenides.•Mechanically and thermally stable at ambient temperatures.•More malleable than other Pd and Pt-based dichalcogenides.•Absorb/emit light at the infrared/ultraviolet levels making them suitable for optoelectronic devices.