{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,16]],"date-time":"2026-04-16T21:04:14Z","timestamp":1776373454808,"version":"3.51.2"},"reference-count":44,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2024,3,5]],"date-time":"2024-03-05T00:00:00Z","timestamp":1709596800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100018571","name":"Guangxi Science and Technology Base and talent Special project","doi-asserted-by":"publisher","award":["AD23026040"],"award-info":[{"award-number":["AD23026040"]}],"id":[{"id":"10.13039\/501100018571","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100018571","name":"Guangxi Science and Technology Base and talent Special project","doi-asserted-by":"publisher","award":["AD23023008"],"award-info":[{"award-number":["AD23023008"]}],"id":[{"id":"10.13039\/501100018571","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100018571","name":"Guangxi Science and Technology Base and talent Special project","doi-asserted-by":"publisher","award":["AC22080003"],"award-info":[{"award-number":["AC22080003"]}],"id":[{"id":"10.13039\/501100018571","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100018571","name":"Guangxi Science and Technology Base and talent Special project","doi-asserted-by":"publisher","award":["BB31200014"],"award-info":[{"award-number":["BB31200014"]}],"id":[{"id":"10.13039\/501100018571","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Guangxi Science and Technology Program","award":["AD23026040"],"award-info":[{"award-number":["AD23026040"]}]},{"name":"Guangxi Science and Technology Program","award":["AD23023008"],"award-info":[{"award-number":["AD23023008"]}]},{"name":"Guangxi Science and Technology Program","award":["AC22080003"],"award-info":[{"award-number":["AC22080003"]}]},{"name":"Guangxi Science and Technology Program","award":["BB31200014"],"award-info":[{"award-number":["BB31200014"]}]},{"name":"High luminous efficiency and long life DUV LED technology","award":["AD23026040"],"award-info":[{"award-number":["AD23026040"]}]},{"name":"High luminous efficiency and long life DUV LED technology","award":["AD23023008"],"award-info":[{"award-number":["AD23023008"]}]},{"name":"High luminous efficiency and long life DUV LED technology","award":["AC22080003"],"award-info":[{"award-number":["AC22080003"]}]},{"name":"High luminous efficiency and long life DUV LED technology","award":["BB31200014"],"award-info":[{"award-number":["BB31200014"]}]},{"name":"Disinfection Robot Based on High Power AlGaN-based UVLEDs","award":["AD23026040"],"award-info":[{"award-number":["AD23026040"]}]},{"name":"Disinfection Robot Based on High Power AlGaN-based UVLEDs","award":["AD23023008"],"award-info":[{"award-number":["AD23023008"]}]},{"name":"Disinfection Robot Based on High Power AlGaN-based UVLEDs","award":["AC22080003"],"award-info":[{"award-number":["AC22080003"]}]},{"name":"Disinfection Robot Based on High Power AlGaN-based UVLEDs","award":["BB31200014"],"award-info":[{"award-number":["BB31200014"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>AlGaN-based LEDs are promising for many applications in deep ultraviolet fields, especially for water-purification projects, air sterilization, fluorescence sensing, etc. However, in order to realize these potentials, it is critical to understand the factors that influence the optical and electrical properties of the device. In this work, AlxGa1\u2212xN (x = 0.24, 0.34, 0.47) epilayers grown on c-plane patterned sapphire substrate with GaN template by the metal organic chemical vapor deposition (MOCVD). It is demonstrated that the increase of the aluminum content leads to the deterioration of the surface morphology and crystal quality of the AlGaN epitaxial layer. The dislocation densities of AlxGa1\u2212xN epilayers were determined from symmetric and asymmetric planes of the \u03c9-scan rocking curve and the minimum value is 1.01 \u00d7 109 cm\u22122. The (101\u00af5) plane reciprocal space mapping was employed to measure the in-plane strain of the AlxGa1\u2212xN layers grown on GaN. The surface barrier heights of the AlxGa1\u2212xN samples derived from XPS are 1.57, 1.65, and 1.75 eV, respectively. The results of the bandgap obtained by PL spectroscopy are in good accordance with those of XRD. The Hall mobility and sheet electron concentration of the samples are successfully determined by preparing simple indium sphere electrodes.<\/jats:p>","DOI":"10.3390\/molecules29051152","type":"journal-article","created":{"date-parts":[[2024,3,5]],"date-time":"2024-03-05T03:03:20Z","timestamp":1709607800000},"page":"1152","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Optical and Electrical Properties of AlxGa1\u2212xN\/GaN Epilayers Modulated by Aluminum Content"],"prefix":"10.3390","volume":"29","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1813-9495","authenticated-orcid":false,"given":"Wenwang","family":"Wei","sequence":"first","affiliation":[{"name":"Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, China"},{"name":"Guangxi Key Laboratory of Calcium Carbonate Resources Comprehensive Utilization, College of Materials and Chemical Engineering, Hezhou University, Hezhou 542899, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yanlian","family":"Yang","sequence":"additional","affiliation":[{"name":"Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yi","family":"Peng","sequence":"additional","affiliation":[{"name":"Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mudassar","family":"Maraj","sequence":"additional","affiliation":[{"name":"Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2936-767X","authenticated-orcid":false,"given":"Wenhong","family":"Sun","sequence":"additional","affiliation":[{"name":"Research Center for Optoelectronic Materials and Devices, School of Physical Science & Technology, Guangxi University, Nanning 530004, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,3,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"22059","DOI":"10.1038\/s41598-020-79135-y","article-title":"Dual-functional ultraviolet photodetector with graphene electrodes on AlGaN\/GaN heterostructure","volume":"10","author":"Pandit","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"141101","DOI":"10.1063\/5.0141568","article-title":"M-plane AlGaN digital alloy for microwire UV-B LEDs","volume":"122","author":"Lucie","year":"2023","journal-title":"Appl. Phys. Lett."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"164797","DOI":"10.1016\/j.ijleo.2020.164797","article-title":"An ultra-sensitive AlGaN\/AlN\/GaN\/AlGaN photodetector: Proposal and investigation","volume":"217","author":"Khaouani","year":"2020","journal-title":"Optik"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"127184","DOI":"10.1016\/j.jcrysgro.2023.127184","article-title":"Low stress AlGaN\/GaN heterojuction with AlGaN buffer grown on 6-inch semi-insulating SiC substrate","volume":"611","author":"Daqing","year":"2023","journal-title":"J. Cryst. Growth"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"105386","DOI":"10.1016\/j.mssp.2020.105386","article-title":"Improved performance of AlGaN\/GaN HEMT based H+ sensors by surface hydroxylation treatment","volume":"121","author":"Xue","year":"2021","journal-title":"Mater. Sci. Semicond. Process"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"127106","DOI":"10.1016\/j.jcrysgro.2023.127106","article-title":"Design of normally-off p-GaN\/AlGaN\/GaN heterojunction field-effect transistors with re-grown AlGaN barrier","volume":"607","author":"Xiaobiao","year":"2023","journal-title":"J. Cryst. Growth"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"152108","DOI":"10.1063\/5.0020359","article-title":"Polarization engineering via InAlN\/AlGaN heterostructures for demonstration of normally-off AlGaN channel field effect transistors","volume":"117","author":"Li","year":"2020","journal-title":"Appl. Phys. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"39695","DOI":"10.1364\/OE.505792","article-title":"Influence of growth interruption on the morphology and luminescence properties of AlGaN\/GaN ultraviolet multi-quantum wells","volume":"31","author":"Hou","year":"2023","journal-title":"Opt. Express"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"024009","DOI":"10.1149\/2162-8777\/ab6833","article-title":"Review\u2014Review of Research on AlGaN MOCVD Growth","volume":"9","author":"Tang","year":"2020","journal-title":"ECS J. Solid State Sci. Technol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"663","DOI":"10.1039\/C8AN01770K","article-title":"Electrical detection of trace zinc ions with an extended gate-AlGaN\/GaN high electron mobility sensor","volume":"144","author":"Gu","year":"2019","journal-title":"Analyst"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1016\/j.sse.2019.01.004","article-title":"Degradation and failure mechanism of AlGaN-based UVC-LEDs","volume":"156","author":"Ma","year":"2019","journal-title":"Solid-State Electron."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"152283","DOI":"10.1016\/j.jallcom.2019.152283","article-title":"Improvement in surface morphology and 2DEG properties of AlGaN\/GaN HEMT","volume":"815","author":"Narang","year":"2020","journal-title":"J. Alloys Compd."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"111508","DOI":"10.1016\/j.mee.2021.111508","article-title":"2DEG transport properties over temperature for AlGaN\/GaN HEMT and AlGaN\/InGaN\/GaN pHEMT","volume":"238","author":"Khan","year":"2021","journal-title":"Microelectron. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Sun, Y., Wang, Y., Tang, J., Wang, W., Huang, Y., and Kuang, X. (2019). A Breakdown Enhanced AlGaN\/GaN Schottky Barrier Diode with the T-Anode Position Deep into the Bottom Buffer Layer. Micromachines, 10.","DOI":"10.3390\/mi10020091"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"262102","DOI":"10.1063\/1.4730951","article-title":"Correlation between threading dislocation density and sheet resistance of AlGaN\/AlN\/GaN heterostructures grown by plasma-assisted molecular beam epitaxy","volume":"100","author":"Kaun","year":"2012","journal-title":"Appl. Phys. Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"151190","DOI":"10.1016\/j.apsusc.2021.151190","article-title":"Surface sensibility and stability of AlGaN\/GaN ion-sensitive field-effect transistors with high Al-content AlGaN barrier layer","volume":"570","author":"Jiyu","year":"2021","journal-title":"Appl. Surf. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"385","DOI":"10.1039\/D0CE01426E","article-title":"MOCVD of AlN on epitaxial graphene at extreme temperatures","volume":"23","author":"Ivanov","year":"2021","journal-title":"CrystEngComm"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1021\/acsnanoscienceau.2c00041","article-title":"Self-Induced Core-Shell InAlN Nanorods: Formation and Stability Unraveled by Ab Initio Simulations","volume":"3","author":"Hsiao","year":"2023","journal-title":"ACS Nanosci Au"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"151641","DOI":"10.1016\/j.apsusc.2021.151641","article-title":"Phase transition and bandgap engineering in B1-xAlxN alloys: DFT calculations and experiments","volume":"575","author":"Zhang","year":"2022","journal-title":"Appl. Surf. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"106982","DOI":"10.1016\/j.mssp.2022.106982","article-title":"Challenges in material processing and reliability issues in AlGaN\/GaN HEMTs on silicon wafers for future RF power electronics & switching applications: A critical review","volume":"151","author":"Ajayan","year":"2022","journal-title":"Mater. Sci. Semicond. Process."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Xu, R., Kang, Q., Zhang, Y., Zhang, X., and Zhang, Z. (2023). Research Progress of AlGaN-Based Deep Ultraviolet Light-Emitting Diodes. Micromachines, 14.","DOI":"10.3390\/mi14040844"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"122106","DOI":"10.1016\/j.matchemphys.2019.122106","article-title":"Electronic properties and oxygen chemisorption at AlxGa1\u2212xN surfaces","volume":"239","author":"Mishra","year":"2020","journal-title":"Mater. Chem. Phys."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"449","DOI":"10.1007\/s00339-020-03645-9","article-title":"Comparison of electrical and interfacial characteristics between atomic-layer-deposited AlN and AlGaN on a GaN substrate","volume":"126","author":"Kim","year":"2020","journal-title":"Appl. Phys. A"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1016\/j.jallcom.2015.09.102","article-title":"Structural and electrical characteristics of GaN, n-GaN and AlxGa1\u2212xN","volume":"656","author":"Arivazhagan","year":"2016","journal-title":"J. Alloys Compd."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2521","DOI":"10.1007\/s11664-020-08733-3","article-title":"Characterization of the Electrical Properties of a Double Heterostructure GaN\/AlGaN Epitaxial Layer with an AlGaN Interlayer","volume":"50","author":"Meng","year":"2021","journal-title":"J. Electron. Mater."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1002\/pssr.201004290","article-title":"Mg-doped Al0.85Ga0.15N layers grown by hot-wall MOCVD with low resistivity at room temperature","volume":"4","author":"Nilsson","year":"2010","journal-title":"Phys. Status Solidi (RRL) Rapid Res. Lett."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"890","DOI":"10.1557\/S1092578300003574","article-title":"Doping of AlGaN Alloys","volume":"4","author":"Stampfl","year":"1999","journal-title":"MRS Internet J. Nitride Semicond. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"182405","DOI":"10.1007\/s11432-022-3694-4","article-title":"Boosted high-temperature electrical characteristics of AlGaN\/GaN HEMTs with rationally designed compositionally graded AlGaN back barriers","volume":"66","author":"Zhang","year":"2023","journal-title":"Sci. China Inf. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1007\/s13391-014-4219-y","article-title":"Performance improvements of AlGaN\/GaN HEMTs by strain modification and unintentional carbon incorporation","volume":"11","author":"Luong","year":"2015","journal-title":"Electron. Mater. Lett."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"135097","DOI":"10.1016\/j.matlet.2023.135097","article-title":"Improved crystal quality of AlGaN by Al ion-implantation sapphire substrate","volume":"351","author":"Tao","year":"2023","journal-title":"Mater. Lett."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"675","DOI":"10.1007\/s13391-015-4424-3","article-title":"Effect of fluctuation in Al incorporation on the microstructure, bond lengths, and surface properties of an AlxGa1\u2212xN epitaxial layer","volume":"11","author":"Wang","year":"2015","journal-title":"Electron. Mater. Lett."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"4335","DOI":"10.1103\/PhysRevB.48.4335","article-title":"Electronic, optical, and structural properties of some wurtzite crystals","volume":"48","author":"Xu","year":"1993","journal-title":"Phys. Rev. B"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Monemar, B., Bergman, J., and Buyanova, I. (2021). GaN and Related Materials: Optical Characterisation of GaN and Related Materials, CRC Press.","DOI":"10.1201\/9781003211082-4"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"896","DOI":"10.1063\/1.326007","article-title":"Optical properties of AlN epitaxial thin films in the vacuum ultraviolet region","volume":"50","author":"Yamashita","year":"1979","journal-title":"J. Appl. Phys."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Wei, W., Peng, Y., Yang, Y., Xiao, K., Maraj, M., Yang, J., Wang, Y., and Sun, W. (2022). Study of Defects and Nano-patterned Substrate Regulation Mechanism in AlN Epilayers. Nanomaterials, 12.","DOI":"10.3390\/nano12223937"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"2486","DOI":"10.1007\/s11664-013-2632-x","article-title":"Structural and carrier dynamics of GaN and AlGaN-based double heterostructures in the UV region","volume":"42","author":"Arivazhagan","year":"2013","journal-title":"J. Electron. Mater."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.jcrysgro.2016.12.089","article-title":"Dislocation densities reduction in MBE-grown AlN thin films by high-temperature annealing","volume":"461","author":"Nemoz","year":"2017","journal-title":"J. Cryst. Growth"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"094006","DOI":"10.1088\/0268-1242\/28\/9\/094006","article-title":"Measuring the composition of AlGaN layers in GaN based structures grown on 150 mm Si substrates using (2\u20090\u20095) reciprocal space maps","volume":"28","author":"Wallis","year":"2013","journal-title":"Semicond. Sci. Technol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"10172","DOI":"10.1038\/s41598-019-46628-4","article-title":"Strain-stress study of AlxGa1\u2212xN\/AlN heterostructures on c-plane sapphire and related optical properties","volume":"9","author":"Feng","year":"2019","journal-title":"Sci. Rep."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"157487","DOI":"10.1016\/j.jallcom.2020.157487","article-title":"Comparative spectroscopic studies of MOCVD grown AlN films on Al2O3 and 6H\u2013SiC","volume":"857","author":"Yin","year":"2021","journal-title":"J. Alloys Compd."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"363","DOI":"10.1016\/j.jallcom.2014.07.170","article-title":"Studies on dislocation and surface morphology of AlxGa1\u2212xN\/GaN heterostructures grown by MOCVD","volume":"616","author":"Loganathan","year":"2014","journal-title":"J. Alloys Compd."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1707","DOI":"10.1063\/1.126143","article-title":"Dislocation scattering in a two-dimensional electron gas","volume":"76","author":"Jena","year":"2000","journal-title":"Appl. Phys. Lett."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"075016","DOI":"10.1088\/1361-6641\/abfe9b","article-title":"Transport properties of AlGaN\/GaN HEMT structures with back barrier: Impact of dislocation density and improved design","volume":"36","year":"2021","journal-title":"Semicond. Sci. Technol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"113510","DOI":"10.1063\/1.2932156","article-title":"Morphology and microstructure evolution of AlxGa1\u2212xN epilayers grown on GaN\/sapphire templates with AlN interlayers observed by transmission electron microscopy","volume":"103","author":"Lu","year":"2008","journal-title":"J. Appl. Phys."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/29\/5\/1152\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T14:09:21Z","timestamp":1760105361000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/29\/5\/1152"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,3,5]]},"references-count":44,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2024,3]]}},"alternative-id":["molecules29051152"],"URL":"https:\/\/doi.org\/10.3390\/molecules29051152","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,3,5]]}}}