Theoretical design of a shallow donor in diamond by lithium-nitrogen codoping

We propose a new substitutional impurity complex in diamond composed of a lithium atom that is tetrahedrally coordinated by four nitrogen atoms (LiN(4)). Density functional calculations are consistent with the hydrogenic impurity model, both supporting the prediction that this complex is a shallow donor with an activation energy of 0.27±0.06 eV. Three paths to the experimental realization of the LiN(4) complex in diamond are proposed and theoretically analyzed.