Programme

O.4 -- Oral, VCTP-51

Date: Monday, 3 August 2026

Time: 14:40 - 15:00

Ab initio Simulation for Electronic Transport in Charged Defect Materials

Ngoc Linh Nguyen

MSE, Phenikaa University

Predictive simulations of charge transport from first principles are crucial for the rational design of semiconductor devices. Although electron--phonon interactions can now be routinely described using density functional theory (DFT) combined with scattering-based transport theories, a comparable treatment of carrier scattering by defects, particularly charged defects, remains elusive. The challenge arises from the coexistence of short-range defect perturbations and long-range screened Coulomb interactions, which have thus far been treated predominantly using simplified models. Here, we introduce a fully ab initio framework that combines a finite-field approach within many-body perturbation theory [1] with DFT to accurately determine the screening response associated with charged defects. The resulting electron--defect scattering rates are incorporated into the Boltzmann transport equation to predict carrier mobilities without empirical parameters. Applying this approach to vacancy defects in monolayer MoS2, we quantify the role of charged defects in limiting charge transport. Our method establishes a general route for ab initio simulations of defect-limited transport in low-dimensional materials and substantially extends the applicability of first-principles transport theory to complex materials relevant to electronic, energy, and quantum technologies. Ref: [1] Ngoc Linh Nguyen et al. Phys. Rev. Lett. 122, 237402 (2019).

Presenter: Nguyen Ngoc Linh