Abstract <p>In this study, the effects of co-doping lithium (Li), boron (B), and phosphorus (P) in polycrystalline diamond films to enhance charge transport for power electronic&#xa0;and&#xa0;quantum device&#xa0;applications were investigated. Ion implantation followed by rapid thermal annealing was used to introduce dopants into the diamond lattice. Structural characterization via secondary ion mass spectrometry (SIMS), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HR-TEM) revealed dopant distribution and crystallographic changes. Electrical properties, measured using the Van der Pauw method for Hall measurements, showed a carrier concentration of 2.88 × 10⁹&#xa0;cm⁻³ and mobility of 555.4 cm²/V s at room temperature. The co-doped films demonstrated superior performance over single-doped and in situ co-doped counterparts, with reduced scattering and enhanced mobility, attributed to the suppression of vacancy defect states. This co-doping strategy shows promise for advancing diamond-based electronic and quantum devices.</p> Graphical abstract <p></p>