Abstract
The formation and stabilization of co-doped defect complexes in diamond are of significant interest for overcoming the doping asymmetry. In this work, we report the formation of Li-N4 complexes in nanocrystalline diamond films via lithium-ion implantation followed by annealing. Electrical transport measurements reveal that carrier-activated conduction at room temperature can be achieved by optimizing the implantation and annealing conditions. Fourier-transform infrared (FTIR) spectroscopy showed a decrease in detectable nitrogen concentration, accompanied by the conversion of A-centers to B-centers, suggesting the formation of Li-N4 complexes. Atom Probe Tomography (APT) further confirms the uniform incorporation of lithium and nitrogen in the lattice without clustering or segregation. These results provide direct experimental evidence for the formation of Li-N4 complexes in diamond, demonstrating a viable pathway to engineer a stable n-type dopant in diamond. This work lays the groundwork for future device applications and advances in the emerging field of diamondtronics.
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•Lithium implanted into nanocrystalline diamond films grown under nitrogen-rich conditions.•Room temperature carrier activation observed in Li-N co-doped nanocrystalline diamond films by optimizing the implantation fluence and post-implantation annealing.•Experimentally demonstrated the formation of Li-N4 complexes in diamond.•Established a pathway to the development of diamond-based electronic and quantum devices under the emerging field of diamondtronics.