Multi-scale approach to first-principles electron transport beyond 100 nm

Area of Science:

• Computational physics and materials science.
• Quantum chemistry and condensed matter physics.

Background:

• Accurate modeling of novel electronic devices requires methods that bridge atomic-level quantum chemistry and larger device scales.
• Existing methods struggle to capture critical features like surfaces, defects, and interfaces in larger device simulations.

Purpose of the Study:

• To present a novel multi-scale computational method for simulating electronic currents in large-area ( > 100 nm²) two-dimensional electronic devices.
• To enable atomistic, quantum-chemical level descriptions of device operation, including perturbed regions and interfaces.

Main Methods:

• A multi-scale approach embedding multiple density functional theory (DFT) perturbed regions within a larger DFT-parametrized tight-binding model.
• Simulation of electronic currents in pristine, defected, and nanoporous graphene devices.
• Utilizing chemically accurate contacts simulating scanning tunneling microscopy probes.

Main Results:

• Demonstration of a viable multi-scale method for calculating electronic currents in large 2D electronic systems.
• Successful application to graphene devices, showcasing the ability to model defects and nanoporous structures.
• Insights into current propagation influenced by material structure and contacts.

Conclusions:

• The presented multi-scale method offers a powerful tool for studying electronic transport in complex, large-scale low-dimensional materials.
• This approach addresses key challenges in simulating realistic electronic devices with atomic precision.
• Further development and application of this method can advance the design and understanding of novel electronic devices.