Electronic structure of rare-earth erbium-doped platinum diselenide: A density functional theory study

The effect of rare-earth erbium (Er) doping on the electronic structure of platinum diselenide (PtSe₂) as a 2D transition metal dichalcogenide was studied using density functional theory (DFT). Our DFT calculations showed that Er dopant in PtSe₂ led to the formation of additional states in the valence and conduction bands, and new localized states within the band gap of PtSe₂. The orbital-resolved density of states revealed that the 4f orbitals of the dopant Er atom strongly impact the electronic structure of the monolayer PtSe₂ and induce spin-polarized localized states. Simultaneously, in addition to a significant increase in the PtSe₂ surface energy (52-fold) due to Er doping (from 7.94 × 10⁻⁵ to 4.16 × 10⁻³ eV/Ų), the formation energy of the Er-doped PtSe₂ (−328.72 kJ/mol) compared to the pristine PtSe₂ (−326.52 kJ/mol) indicates that Er doping has made the PtSe₂ system thermodynamically more stable. The results of this study can be used as a guide to design devices for optoelectronic applications such as sensors.