Mechanical decoupling epitaxy via compliant microdisks yields relaxed transferable AlGaN across broad compositions

Mechanical decoupling epitaxy via compliant microdisks yields relaxed transferable AlGaN across broad compositions | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Mechanical decoupling epitaxy via compliant microdisks yields relaxed transferable AlGaN across broad compositions Pierre-Marie Coulon, Léa Lacomblez, Maud Nemoz, Ileana Florea, and 8 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9009585/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version 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 Al0.15Ga0.85N microdisks supported by GaN pillars accommodate strain during subsequent regrowth, enabling fully relaxed, crack-free AlxGa1-xN up to 82% Al and threading dislocation densities comparable to the initial GaN template (~2-5 × 10⁸ 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. Physical sciences/Materials science/Materials for optics/Lasers, LEDs and light sources Physical sciences/Materials science/Materials for devices mechanical decoupling epitaxy AlGaN microdisk compliance threading dislocation density transfer UV optoelectronics Full Text Additional Declarations There is NO Competing Interest. Supplementary Files PMCoulonSupplementaryInformationNatureMaterials.pdf Supplementary Information for Mechanical decoupling epitaxy via compliant microdisks yields relaxed transferable AlGaN across broad compositions Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9009585","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":602931691,"identity":"eec8163a-ca58-43f8-955e-fe5a5446e7d5","order_by":0,"name":"Pierre-Marie 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