{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T10:25:31Z","timestamp":1773138331061,"version":"3.50.1"},"reference-count":38,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2025,4,14]],"date-time":"2025-04-14T00:00:00Z","timestamp":1744588800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2025,4,14]],"date-time":"2025-04-14T00:00:00Z","timestamp":1744588800000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["2022.05329.PTDC"],"award-info":[{"award-number":["2022.05329.PTDC"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["2022.09585.BD"],"award-info":[{"award-number":["2022.09585.BD"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UID\/05367\/2020"],"award-info":[{"award-number":["UID\/05367\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Physica Rapid Research Ltrs"],"published-print":{"date-parts":[[2026,2]]},"abstract":"<jats:p>\n                    Gallium oxide is a wide\u2010bandgap semiconductor which has been steadily growing in popularity due to its ultrawide bandgap, suitability for harsh environments, and distinctive optoelectrical properties. Notable applications include deep\u2010UV photodetectors, low\u2010loss waveguides, or even transparent solar cells. RF sputtering stands out among possible techniques for the deposition of  thin films with high quality and at a low cost. By using sapphire substrates, and through thermal annealing, a  alloy can be formed by Al diffusion, which has tunable optoelectrical properties such as the bandgap and breakdown electric field. In this work, techniques such as X\u2010Ray diffraction, Rutherford backscattering spectrometry, Raman spectroscopy, atomic force microscopy, and optical transmission are used to determine the optical properties, morphology, and the composition of the deposited and annealed  thin films. To explore the formation of the  alloy, annealing is performed at variable temperature, in ambient air. It is determined that the bandgap can indeed be tuned between 4.85 and 5.30\u2009eV by varying the annealing temperature, corresponding to an Al molar fraction\n                    <jats:italic>x<\/jats:italic>\n                    between 0 and 43.8%.\n                  <\/jats:p>","DOI":"10.1002\/pssr.202500053","type":"journal-article","created":{"date-parts":[[2025,4,14]],"date-time":"2025-04-14T14:46:41Z","timestamp":1744642001000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Effect of Annealing on Al Diffusion and its Impact on the Properties of Ga\n                    <sub>2<\/sub>\n                    O\n                    <sub>3<\/sub>\n                    Thin Films Deposited on c\u2010Plane Sapphire by RF Sputtering"],"prefix":"10.1002","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-4018-8479","authenticated-orcid":false,"given":"Ana Sofia","family":"Sousa","sequence":"first","affiliation":[{"name":"Instituto de Engenharia de Sistemas e Computadores \u2014 Microssistemas e Nanotecnologias (INESC MN)  9 1000\u2010029 Lisboa Portugal"},{"name":"Instituto de Plasmas e Fus\u00e3o Nuclear Instituto Superior T\u00e9cnico Universidade de Lisboa  9 1000\u2010029 Lisboa Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8566-9245","authenticated-orcid":false,"given":"Duarte M.","family":"Esteves","sequence":"additional","affiliation":[{"name":"Instituto de Engenharia de Sistemas e Computadores \u2014 Microssistemas e Nanotecnologias (INESC MN)  9 1000\u2010029 Lisboa Portugal"},{"name":"Instituto de Plasmas e Fus\u00e3o Nuclear Instituto Superior T\u00e9cnico Universidade de Lisboa  9 1000\u2010029 Lisboa Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6044-5333","authenticated-orcid":false,"given":"Tiago T.","family":"Robalo","sequence":"additional","affiliation":[{"name":"Departamento de F\u00edsica Faculdade de Ci\u00eancias Universidade de Lisboa  9 1000\u2010029 Lisboa Portugal"},{"name":"BioISI\u2014Biosystems and Integrative Sciences Institute Faculdade de Ci\u00eancias Universidade de Lisboa  9 1000\u2010029 Lisboa Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0468-1910","authenticated-orcid":false,"given":"M\u00e1rio S.","family":"Rodrigues","sequence":"additional","affiliation":[{"name":"Departamento de F\u00edsica Faculdade de Ci\u00eancias Universidade de Lisboa  9 1000\u2010029 Lisboa Portugal"},{"name":"BioISI\u2014Biosystems and Integrative Sciences Institute Faculdade de Ci\u00eancias Universidade de Lisboa  9 1000\u2010029 Lisboa Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0986-9880","authenticated-orcid":false,"given":"Lu\u00eds F.","family":"Santos","sequence":"additional","affiliation":[{"name":"Centro de Qu\u00edmica Estrutural Institute of Molecular Sciences and Departamento de Engenharia Qu\u00edmica Instituto Superior T\u00e9cnico Universidade de Lisboa  9 1000\u2010029 Lisboa Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5546-6922","authenticated-orcid":false,"given":"Katharina","family":"Lorenz","sequence":"additional","affiliation":[{"name":"Instituto de Engenharia de Sistemas e Computadores \u2014 Microssistemas e Nanotecnologias (INESC MN)  9 1000\u2010029 Lisboa Portugal"},{"name":"Instituto de Plasmas e Fus\u00e3o Nuclear Instituto Superior T\u00e9cnico Universidade de Lisboa  9 1000\u2010029 Lisboa Portugal"},{"name":"Departamento de Engenharia e Ci\u00eancias Nucleares Instituto Superior T\u00e9cnico Universidade de Lisboa  9 1000\u2010029 Lisboa Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6774-8492","authenticated-orcid":false,"given":"Marco","family":"Peres","sequence":"additional","affiliation":[{"name":"Instituto de Engenharia de Sistemas e Computadores \u2014 Microssistemas e Nanotecnologias (INESC MN)  9 1000\u2010029 Lisboa Portugal"},{"name":"Instituto de Plasmas e Fus\u00e3o Nuclear Instituto Superior T\u00e9cnico Universidade de Lisboa  9 1000\u2010029 Lisboa Portugal"},{"name":"Departamento de Engenharia e Ci\u00eancias Nucleares Instituto Superior T\u00e9cnico Universidade de Lisboa  9 1000\u2010029 Lisboa Portugal"}]}],"member":"311","published-online":{"date-parts":[[2025,4,14]]},"reference":[{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.5006941"},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-6090(02)00202-X"},{"key":"e_1_2_9_4_1","doi-asserted-by":"publisher","DOI":"10.1007\/s43673-021-00033-0"},{"key":"e_1_2_9_5_1","doi-asserted-by":"publisher","DOI":"10.1002\/adom.202002160"},{"key":"e_1_2_9_6_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.5017810"},{"key":"e_1_2_9_7_1","volume-title":"Springer Series In Materials Science","author":"Higashiwaki M.","year":"2020"},{"key":"e_1_2_9_8_1","first-page":"36","volume-title":"IEEE Spectrum","author":"Jessen G. H.","year":"2021"},{"key":"e_1_2_9_9_1","doi-asserted-by":"publisher","DOI":"10.1088\/1674-1056\/28\/1\/017105"},{"key":"e_1_2_9_10_1","doi-asserted-by":"publisher","DOI":"10.1039\/C9TC02055A"},{"key":"e_1_2_9_11_1","doi-asserted-by":"publisher","DOI":"10.1063\/5.0027067"},{"key":"e_1_2_9_12_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.5133845"},{"key":"e_1_2_9_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/B978-0-12-814521-0.00003-8"},{"key":"e_1_2_9_14_1","doi-asserted-by":"publisher","DOI":"10.1149\/2.0141907jss"},{"key":"e_1_2_9_15_1","doi-asserted-by":"publisher","DOI":"10.1002\/pssa.201900385"},{"key":"e_1_2_9_16_1","first-page":"49","volume-title":"UV And Higher Energy Photonics: From Materials To Applications","author":"Mishra M.","year":"2022"},{"key":"e_1_2_9_17_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jeurceramsoc.2005.06.039"},{"key":"e_1_2_9_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jallcom.2020.153755"},{"key":"e_1_2_9_19_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10854-014-2066-0"},{"key":"e_1_2_9_20_1","doi-asserted-by":"publisher","DOI":"10.1116\/1.4963376"},{"key":"e_1_2_9_21_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.4940763"},{"key":"e_1_2_9_22_1","doi-asserted-by":"publisher","DOI":"10.1063\/5.0182500"},{"key":"e_1_2_9_23_1","doi-asserted-by":"publisher","DOI":"10.1002\/admi.202400122"},{"key":"e_1_2_9_24_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.5054943"},{"key":"e_1_2_9_25_1","first-page":"98","volume":"1918","author":"Scherrer P.","year":"1918","journal-title":"Nachrichten von der Gesellschaft der Wissenschaften zu G\u00f6ttingen, Mathematisch\u2010Physikalische Klasse"},{"key":"e_1_2_9_26_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10832-021-00263-6"},{"key":"e_1_2_9_27_1","doi-asserted-by":"publisher","DOI":"10.1088\/0959-5309\/56\/3\/303"},{"key":"e_1_2_9_28_1","doi-asserted-by":"publisher","DOI":"10.1107\/S0021889883010493"},{"key":"e_1_2_9_29_1","doi-asserted-by":"publisher","DOI":"10.1080\/01418619808221225"},{"key":"e_1_2_9_30_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.4915627"},{"key":"e_1_2_9_31_1","doi-asserted-by":"publisher","DOI":"10.1016\/S1386-1425(98)00312-6"},{"key":"e_1_2_9_32_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevB.5.3144"},{"key":"e_1_2_9_33_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.3421540"},{"key":"e_1_2_9_34_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.3271697"},{"key":"e_1_2_9_35_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.1940137"},{"key":"e_1_2_9_36_1","doi-asserted-by":"publisher","DOI":"10.1021\/jp075835b"},{"key":"e_1_2_9_37_1","doi-asserted-by":"publisher","DOI":"10.1140\/epjp\/s13360-021-01629-z"},{"key":"e_1_2_9_38_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.nimb.2007.10.044"},{"key":"e_1_2_9_39_1","doi-asserted-by":"publisher","DOI":"10.2478\/s11534-011-0096-2"}],"container-title":["physica status solidi (RRL) \u2013 Rapid Research Letters"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/pssr.202500053","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/pssr.202500053","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/pssr.202500053","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,9]],"date-time":"2026-03-09T04:26:26Z","timestamp":1773030386000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/pssr.202500053"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,4,14]]},"references-count":38,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2026,2]]}},"alternative-id":["10.1002\/pssr.202500053"],"URL":"https:\/\/doi.org\/10.1002\/pssr.202500053","archive":["Portico"],"relation":{},"ISSN":["1862-6254","1862-6270"],"issn-type":[{"value":"1862-6254","type":"print"},{"value":"1862-6270","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,4,14]]},"assertion":[{"value":"2025-02-04","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-04-14","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e202500053"}}