| Abstract Scope |
Spin defects in 4H-SiC, such as the divacancy (VV), have emerged as promising solid-state platforms for quantum telecommunications and photonics. The anisotropic hexagonal crystal structure of 4H-SiC gives rise to crystallographically inequivalent lattice sites that directly influence divacancy configurations and stability. However, realizing reliable defect engineering requires precise control over VV formation kinetics. Here, we combine density functional theory calculations with kinetic Monte Carlo simulations to uncover defect migration pathways and identify optimal thermal annealing conditions for VV formation and stabilization. We find that the optimal temperature for maximizing VV formation lies between 1200 K and 1300 K. Furthermore, among the four VV configurations in 4H-SiC (hh, kk, kh, and hk), the dominant VV species depends not only on energetic barriers but also on entropy and pathway availability: the kh-type VV dominates at lower temperatures, transitioning to hk-type dominance at higher temperatures. These findings provide design guidelines for controlling thermally activated defect kinetics to achieve atomic-scale localization of spin defects. |