Atomic Effective Pseudopotentials for Semiconductors

TL;DR

This paper introduces a method to derive atomic effective pseudopotentials (AEPs) from density functional theory, enabling efficient simulation of large semiconductor nanostructures without fitting procedures.

Contribution

The authors develop a parameter-free, transferable approach to generate AEPs from DFT, simplifying large-scale semiconductor simulations and accurately capturing band offsets.

Findings

AEPs accurately reproduce DFT results for strained structures

AEPs effectively model quantum wells and alloys

20 AEPs created for common semiconductor materials

Abstract

We derive an analytic connection between the screened self-consistent effective potential from density functional theory (DFT) and atomic effective pseudopotentials (AEPs). The motivation to derive AEPs is to address structures with thousands to hundred thousand atoms, as given in most nanostructures. The use of AEPs allows to bypass a self-consistent procedure and to address eigenstates around a certain region of the spectrum (e.g., around the band gap). The bulk AEP construction requires two simple DFT calculations of slightly deformed elongated cells. The ensuing AEPs are given on a fine reciprocal space grid, including the small reciprocal vector components, are free of parameters, and involve no fitting procedure. We further show how to connect the AEPs of different bulk materials, which is necessary to obtain accurate band offsets. We derive a total of 20 AEPs for III-V, II-VI and group IV semiconductors and demonstrate their accuracy and transferability by comparison to DFT calculations of strained bulk structures, quantum wells with varying thickness, and semiconductor alloys.