Determine the microscopic origin of acoustically active DX-center traps

Determine the microscopic origin of the traps responsible for acoustically induced DX-center restructuring in GaN/Al0.2Ga0.8N/AlN heterostructures, including whether they arise from oxygen donors, compositional fluctuations in the AlxGa1−xN alloy, or another defect source.

Background

The paper interprets the persistent acoustoconductivity and ultrasound-induced lattice expansion in terms of metastable DX centers whose energies and configurations are modified by dynamic deformation. However, the microscopic identity of the defects acting as these DX centers is not established. The authors identify oxygen donors and compositional fluctuations in the AlxGa1−xN alloy as possible sources, making the defect origin an explicitly unresolved issue relevant to validating and refining the proposed restructuring model.

References

The origin of the traps is still under investigation, with possible sources including oxygen donors or compositional fluctuations in the $\mathrm{Al_xGa_{1 - x}N}$ alloy. Further work is ongoing to clarify the nature of these defects.

— Trap Dynamics and Conductivity Changes in AlGaN/GaN Heterostructures Under Ultrasonic Loading  (2609.01080 - Kaliuzhnyi et al., 1 Sep 2026) in Section 3.4, “DX Center Restructuring Model”