{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T15:05:33Z","timestamp":1785423933383,"version":"3.56.0"},"reference-count":48,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T00:00:00Z","timestamp":1784505600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100018928","name":"Westlake University","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100018928","id-type":"DOI","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/05hfa4n20","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Heteroepitaxy of single-crystalline GaN on glass represents a promising approach for low-cost, large-area optoelectronics, yet the amorphous nature of glass inherently lacks the long-range atomic order required for crystalline templating. To address this limitation, we introduce a distinctive topologically optimized pre-orienting layer (TOPL) strategy based on Cu (111) thin films, enabling the growth of an AlN (0002) buffer layer and thus achieving high-quality GaN micropyramid array epitaxy on amorphous glass. First, by introducing a disconnected Cu thin film, the grain boundaries during annealing are effectively confined within the non-epitaxial region. This process to a large extent overcomes the polycrystallization of metal templates on amorphous glass. Then, experiments demonstrated that under multiply connected configurations, the Cu (111) surface not only preserves the grain-boundary-confining property but also exhibits notable surface smoothness. Among the evaluated symmetries, the sixfold symmetry structure achieves the optimum atomic-level flatness with a root-mean-square roughness of 0.395 nm. Building upon this TOPL architecture, c-axis-oriented GaN micropyramids were grown via selective area epitaxy. The glass-based GaN micropyramid demonstrates comparable crystalline quality (threading dislocation density from a single lamella: 5.46 \u00d7 108 cm\u22122) to those grown on sapphire substrates, while exhibiting reduced stress and comparable cathodoluminescence full width at half maximum. Overall, the TOPL strategy presents a promising pathway toward low-cost GaN micropyramid epitaxy on glass substrates.<\/jats:p>","DOI":"10.3390\/ma19143105","type":"journal-article","created":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T06:09:09Z","timestamp":1784527749000},"page":"3105","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Topologically Optimized Copper Pre-Orienting Layer Enabled High-Quality GaN Micropyramid Epitaxy on Amorphous Glass"],"prefix":"10.3390","volume":"19","author":[{"given":"Yaqing","family":"Ma","sequence":"first","affiliation":[{"name":"Zhejiang University, Hangzhou 310027, China"},{"name":"Advanced Solid-State Semiconductor Lab, School of Engineering, Westlake University, Hangzhou 310024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Junwei","family":"Cao","sequence":"additional","affiliation":[{"name":"Advanced Solid-State Semiconductor Lab, School of Engineering, Westlake University, Hangzhou 310024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-0115-6748","authenticated-orcid":false,"given":"Huaze","family":"Zhu","sequence":"additional","affiliation":[{"name":"Advanced Solid-State Semiconductor Lab, School of Engineering, Westlake University, Hangzhou 310024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-8677-4185","authenticated-orcid":false,"given":"Tong","family":"Jiang","sequence":"additional","affiliation":[{"name":"Advanced Solid-State Semiconductor Lab, School of Engineering, Westlake University, Hangzhou 310024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-9849-943X","authenticated-orcid":false,"given":"Yuqiao","family":"Zheng","sequence":"additional","affiliation":[{"name":"Zhejiang University, Hangzhou 310027, China"},{"name":"College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1038\/nature10677","article-title":"Nanometre-scale electronics with III-V compound semiconductors","volume":"479","year":"2011","journal-title":"Nature"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"223","DOI":"10.1038\/nature10970","article-title":"Layered boron nitride as a release layer for mechanical transfer of GaN-based devices","volume":"484","author":"Kobayashi","year":"2012","journal-title":"Nature"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2300112","DOI":"10.1002\/adom.202300112","article-title":"Microdisplays: Mini-LED, Micro-OLED, and Micro-LED","volume":"12","author":"Miao","year":"2024","journal-title":"Adv. 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R"}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/14\/3105\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T04:13:33Z","timestamp":1784693613000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/14\/3105"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,20]]},"references-count":48,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["ma19143105"],"URL":"https:\/\/doi.org\/10.3390\/ma19143105","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,20]]}}}