Ab initio study of Li and P doped diamond

Li doped, P doped, as well as Li and P doped diamond under different charging conditions were systematically studied using density functional theory. Heyd, Scuseria, and Ernzerhof (HSE06) hybrid functional was used for property calculation. Interstitial Li exhibits n-type doping characteristics, while substitutional Li exhibits p-type doping characteristics. P is doped into the diamond lattice as a substitute impurity, exhibiting n-type donor characteristics. When a Li atom and a P atom are doped in diamond, Li_sP_s is the most stable doping configuration. By adding interstitial Li atoms or P atoms on the basis of Li_sP_s, n-type doping is exhibited, but due to the high defect formation energy and donor ionization energy, it is difficult to form effective n-type doping conductivity. Theoretical calculations demonstrate that the Fermi level has a significant impact on the formation energy of defects with different charges, and adjusting the Fermi level may enhance defect formation and solubility. This presents a pathway for advancing n-type doping techniques.