3 papers
cond-mat.mtrl-sci2024
Nonradiative quenching of EPR signals in germanium-doped AlGaN: evidence for DX-center formation
Jason Forbus, Darshana Wickramaratne, John L. Lyons +1
We present photo-electron paramagnetic resonance (EPR) measurements and first-principles calculations that indicate germanium (Ge) is a DX-center in AlGaN. Our photo-EPR measuremen…
cond-mat.mtrl-sci2024
Direct evidence for carbon incorporation on the nitrogen site in AlN
Darshana Wickramaratne, Mackenzie Siford, Md Shafiqul Islam Mollik +2
We use photo-electron paramagnetic resonance (EPR) measurements and first-principles calculations to identify and explain the properties of carbon in AlN. We present clear evidence…
cond-mat.mtrl-sci2023
Assessing the SCAN functional for deep defects and small polarons in wide-bandgap semiconductors and insulators
Darshana Wickramaratne, John L. Lyons
We find the recently developed strongly constrained and appropriately normed (SCAN) functional, now widely used in calculations of many materials, is not able to reliably describe…