Mechanical decoupling epitaxy via compliant microdisks yields relaxed transferable AlGaN across broad compositions
Abstract
Achieving high-quality, crack-free AlGaN layers across a wide aluminum composition range is critical for ultraviolet optoelectronics but remains challenging due to strain-induced defects from lattice and thermal mismatches. Here we present a mechanical decoupling epitaxy approach wherein compliant Al 0.15 Ga 0.85 N microdisks supported by GaN pillars accommodate strain during subsequent regrowth, enabling fully relaxed, crack-free Al x Ga 1−x N up to 82% Al and threading dislocation densities comparable to the initial GaN template (~ 2–5 × 10 8 cm −2 ). Plastic relaxation via misfit dislocations is confined to the supporting GaN pillars, allowing elastic deformation of the microdisk and preserving the structural quality of the overlayer. The resulting AlGaN micropallets support UVB emission from multiple quantum wells and can be mechanically transferred onto arbitrary substrates without degradation. This strategy decouples strain relaxation from substrate constraints, offering a versatile pathway toward high-quality AlGaN templates and advancing efficient UV micro-optoelectronic device development.
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BibTeX
@article{coulon2026mechanical,
title = {{Mechanical decoupling epitaxy via compliant microdisks yields relaxed transferable AlGaN across broad compositions}},
author = {Pierre-Marie Coulon and Lea Lacomblez and Maud Nemoz and Ileana Florea and Halima Rahmoune and Alexandre Pofelski and Philippe Vennéguès and Sebastien Chenot and Maksym Gromovyi and Nabila Maloufi and Blandine Alloing and Benjamin Damilano},
journal = {Scientific Reports},
year = {2026},
month = sep,
doi = {10.1038/s41598-026-72227-1},
url = {https://hal.science/hal-05851703v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Mechanical decoupling epitaxy via compliant microdisks yields relaxed transferable AlGaN across broad compositions
AU - Pierre-Marie Coulon
AU - Lea Lacomblez
AU - Maud Nemoz
AU - Ileana Florea
AU - Halima Rahmoune
AU - Alexandre Pofelski
AU - Philippe Vennéguès
AU - Sebastien Chenot
AU - Maksym Gromovyi
AU - Nabila Maloufi
AU - Blandine Alloing
AU - Benjamin Damilano
PY - 2026
DA - 2026/09/25
JO - Scientific Reports
DO - 10.1038/s41598-026-72227-1
UR - https://hal.science/hal-05851703v1
AB - Achieving high-quality, crack-free AlGaN layers across a wide aluminum composition range is critical for ultraviolet optoelectronics but remains challenging due to strain-induced defects from lattice and thermal mismatches. Here we present a mechanical decoupling epitaxy approach wherein compliant Al 0.15 Ga 0.85 N microdisks supported by GaN pillars accommodate strain during subsequent regrowth, enabling fully relaxed, crack-free Al x Ga 1−x N up to 82% Al and threading dislocation densities comparable to the initial GaN template (~ 2–5 × 10 8 cm −2 ). Plastic relaxation via misfit dislocations is confined to the supporting GaN pillars, allowing elastic deformation of the microdisk and preserving the structural quality of the overlayer. The resulting AlGaN micropallets support UVB emission from multiple quantum wells and can be mechanically transferred onto arbitrary substrates without degradation. This strategy decouples strain relaxation from substrate constraints, offering a versatile pathway toward high-quality AlGaN templates and advancing efficient UV micro-optoelectronic device development.
SN - 2045-2322
ER -