Accurate Ab-initio Method for Charged Defect Scattering

Charged defects are common scattering sources in carrier transport. However, existing methods for calculating this scattering typically assume specific distributions of unscreened excess charge, such as point charges or Gaussian distributions, which limit accuracy and predictive capability. To address these limitations, we develop a method that constructs and solves the charge density Dyson equation, allowing us to accurately determine the unscreened excess charge. This enables more precise calculations of both nature of the charged defect and carrier transport. We demonstrate our method using the example of charged sulfur vacancies in 2D MoS₂. Notably, we find that electron mobility, limited by charged sulfur vacancies, exhibits a non-monotonic trend as a function of carrier concentration in doped 2D MoS₂, highlighting a distinct transport behavior compared to neutral defects like oxygen substitution. Our work enhances the accuracy of charged defect scattering calculations and deepens the understanding of transport mechanisms governed by carrier concentration in doped systems.