Comprehensive study of exciton luminescence in AlN stacking faults
Phys. Rev. Materials 10, 094602 – Published 3 September, 2026
DOI: https://doi.org/10.1103/tkxc-g94w
Abstract
We have identified the optical signature of a variety of basal plane stacking faults (SFs) in AlN, exhibiting from one to five violations of the wurtzite stacking sequence. The unambiguous assignment of the emission energies to specific SFs was achieved by using a combination of scanning transmission electron microscopy and cathodoluminescence experiments performed on the same lamellae. Additional cathodoluminescence experiments have confirmed the spatially direct or indirect nature of the transitions and the role of polarization fields. Ab initio density functional theory (DFT) calculations for the different SF types were performed to determine their formation energies and electronic structures. SF luminescence energies were calculated using the one-dimensional envelope function approximation to solve the effective-mass Schrödinger equation. We find an excellent agreement between experiments and calculations. In particular, the DFT calculations reveal a crossover from momentum-direct to momentum-indirect recombination in the SFs, accounting for the higher emission energy of I3 relative to I2 SFs. This system provides an attractive platform for investigating spatially and momentum-indirect excitons.
