First principles study on the electronic and optical properties of Yb and La doped diamond

Abstract

The La and Yb doped diamond electronic and optical properties have been investigated through first-principles density functional theory calculations. The findings reveal that the face-centered doping of Yb and La in diamonds results in the most stable energy configurations compared to vertex doping or internal doping. The bandgap widths of these doped systems are reduced from 5.29 eV of pristine diamond to 0.92 eV for Yb and 1.89 eV for La, respectively. Both magnetic moments of La doped and pure diamond are zero, while Yb doped diamond exhibits a magnetic moment of 2.1 μ_B. The static dielectric constant, optical absorption edge, static refractive index, and energy loss features of intrinsic diamond are markedly altered upon doping with La and Yb. Specifically, the static dielectric constants escalate from 4.18 to 43.8 and 71.7 for Yb and La doping, respectively. The optical absorption edges undergo a red shift, while the static refractive indices increase from 2 to 2.5 and 5.5 for La and Yb doping, respectively. Additionally, the peak positions of the energy loss shift from 7.5 eV to 1.8 eV and 3.0 eV for La and Yb doping, respectively. These insights lay a theoretical foundation for the broad applications of diamonds in various fields.