First-principles study of sodium adsorption and diffusion over substitutionally doped phosphorene

Phosphorene, due to its remarkable semiconducting properties, prevailed as principal material of research for decades. The substitutional doping of carbon (C), silicon (Si), oxygen (O) and sulphur (S) atom was reported earlier. DFT studies are done towards the unexplored area of sodium (Na) adsorption and diffusion over these doped phosphorene structures. The effective adsorption energies for C-, Si-, O- and S- doped phosphorene are −3.19 eV, −2.63 eV, −3.12 eV and −2.39 eV respectively. The minimum value of activation energies are 0.68 eV, 0.45 eV, 1.00 eV and 0.26 eV respectively. Hence the diffusion and intercalation–deintercalation process seem to be supportive. The lattice integrity is maintained in the whole process. Good amount of charge transfer shows better conductivity supported by band structure and density of states diagrams. Based on these data, the proposed doped phosphorene configurations can be predicted suitable for further studies towards anode application in Na-ion battery.