Zeeman splitting of shallow donors in GaN

TL;DR

This paper investigates the Zeeman splitting of shallow donor states in cubic and hexagonal GaN using effective mass theory, providing insights into donor energies and the effects of different dopants.

Contribution

It introduces a theoretical approach combining effective mass theory and soft-core pseudopotentials to accurately calculate donor states in GaN.

Findings

Donor ground states range from 29.5 to 33.7 meV.

Hexagonal phase has about 1 meV higher binding energy.

Carbon produces the largest donor binding energy.

Abstract

The Zeeman splitting of the donor spectra in cubic- and hexagonal-GaN are studied using an effective mass theory approach. Soft-core pseudopotentials were used to describe the chemical shift of the different substitutional dopants. The donor ground states calculated range from 29.5 to 33.7 meV, with typically 1 meV higher binding in the hexagonal phase. Carbon is found to produce the largest donor binding energy. The ionization levels and excited states are in excellent agreement with Hall and optical measurements, and suggest the presence of residual C in recent experiments.