{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,25]],"date-time":"2026-09-25T04:59:24Z","timestamp":1790312364917,"version":"4.1.0"},"reference-count":21,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T00:00:00Z","timestamp":1790121600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004608","name":"Natural Science Foundation of Jiangsu Province","doi-asserted-by":"publisher","award":["BK20230235"],"award-info":[{"award-number":["BK20230235"]}],"id":[{"id":"10.13039\/501100004608","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["62304209"],"award-info":[{"award-number":["62304209"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"award":["62304209"],"award-info":[{"award-number":["62304209"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007926","name":"North University of China","doi-asserted-by":"publisher","award":["110141067"],"award-info":[{"award-number":["110141067"]}],"id":[{"id":"10.13039\/501100007926","id-type":"DOI","asserted-by":"publisher"}]},{"award":["110141067"],"award-info":[{"award-number":["110141067"]}],"id":[{"id":"https:\/\/ror.org\/047bp1713","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nanomaterials"],"abstract":"<jats:p>Ultraviolet (UV) photodetectors are essential for flame monitoring, environmental sensing, UV photography, optical communication, and biochemical analysis, and III-nitride quantum-well structures are promising platforms for such devices. Two-dimensional Ti3C2Tx MXene, which combines metallic conductivity with a termination-dependent work function, offers an attractive route to modifying the surface and interface transport of GaN-based photodetectors. The purpose of this work is to determine whether integrating a Ti3C2Tx MXene surface region onto a grating-electrode GaN\/AlGaN asymmetric coupled-quantum-well UV photodetector selectively enhances the photoresponse or predominantly modifies the overall device conductance. The device was fabricated and assessed under 254 nm illumination. Optical and scanning electron microscopy verified the patterned device and the continuous grating region, and the fabrication sequence explained the integration procedure. Static current\u2013voltage (I\u2013V) characteristics of the same device were measured both before and after Ti3C2Tx MXene coverage. Nonlinear transport and a discernible light\u2013dark current gap were present in both states. Before MXene coverage, the device produced a dark current of 1.98 \u03bcA, a net photocurrent of 1.90 \u03bcA, and a light-to-dark current ratio of 1.96 at +3 V; after coverage, the corresponding values were 0.837 mA, 0.835 mA, and 2.00. The increase in the dark current was reproduced on three grating-electrode devices, for which MXene coverage raised the dark current by a factor of between about 4 \u00d7 102 and 1.3 \u00d7 103 depending on the device and the sweep direction, whereas a control structure without the grating electrode remained nearly three orders of magnitude below the MXene-covered devices. Switching the 254 nm source at a fixed bias of +1 V produced reproducible switching between two current levels with a light-to-dark ratio of 2.10\u20132.15; the transitions were completed within the 0.1 s sampling interval. Ti3C2Tx MXene coverage raised the total current level in both electrical states while maintaining a detectable relative light\u2013dark contrast from +1 to +5 V, indicating that the dominant measured change was an increase in device conductance rather than a selective enhancement of the relative photoresponse. Within the scope of this transport study centered on static I\u2013V measurements and supplemented by a single-device time-resolved measurement, the results demonstrate static separation between the dark and 254 nm-illuminated states and modification of the overall electrical transport by MXene coverage on the same device; they do not claim an improvement in photodetector figures of merit, and absolute figures of merit are not reported because the optical power incident on the device was not calibrated.<\/jats:p>","DOI":"10.3390\/nano16191204","type":"journal-article","created":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T16:10:31Z","timestamp":1790179831000},"page":"1204","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Modification of Electrical Transport in a Grating-Electrode GaN\/AlGaN Quantum-Well Device by Ti3C2Tx MXene Under 254 nm Illumination"],"prefix":"10.3390","volume":"16","author":[{"given":"Boning","family":"Wei","sequence":"first","affiliation":[{"name":"School of Semiconductor and Physics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xi","family":"Wei","sequence":"additional","affiliation":[{"name":"School of Semiconductor and Physics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9980-1446","authenticated-orcid":false,"given":"Haibing","family":"Qiu","sequence":"additional","affiliation":[{"name":"School of Semiconductor and Physics, North University of China, Taiyuan 030051, China"},{"name":"State Key Laboratory of Widegap Semiconductor Optoelectronic Materials and Technologies, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5592-3887","authenticated-orcid":false,"given":"Cheng","family":"Lei","sequence":"additional","affiliation":[{"name":"School of Semiconductor and Physics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fengchao","family":"Li","sequence":"additional","affiliation":[{"name":"School of Semiconductor and Physics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ting","family":"Liang","sequence":"additional","affiliation":[{"name":"School of Semiconductor and Physics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1564-1631","authenticated-orcid":false,"given":"Jiangang","family":"Yu","sequence":"additional","affiliation":[{"name":"School of Semiconductor and Physics, North University of China, Taiyuan 030051, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1718-071X","authenticated-orcid":false,"given":"Wenxian","family":"Yang","sequence":"additional","affiliation":[{"name":"Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shulong","family":"Lu","sequence":"additional","affiliation":[{"name":"Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shan","family":"Jin","sequence":"additional","affiliation":[{"name":"Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"7433","DOI":"10.1063\/1.362677","article-title":"Semiconductor ultraviolet detectors","volume":"79","author":"Razeghi","year":"1996","journal-title":"J. Appl. Phys."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"R33","DOI":"10.1088\/0268-1242\/18\/4\/201","article-title":"Wide-bandgap semiconductor ultraviolet photodetectors","volume":"18","author":"Monroy","year":"2003","journal-title":"Semicond. Sci. Technol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1016\/j.mssp.2014.02.054","article-title":"Recent advances in ultraviolet photodetectors","volume":"29","author":"Alaie","year":"2015","journal-title":"Mater. Sci. Semicond. Process."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"4628","DOI":"10.1063\/1.1527994","article-title":"Backilluminated ultraviolet photodetector based on GaN\/AlGaN multiple quantum wells","volume":"81","author":"Zhang","year":"2002","journal-title":"Appl. Phys. Lett."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1401","DOI":"10.1016\/S0038-1101(03)00068-6","article-title":"GaN\/AlGaN back-illuminated multiple-quantum-well Schottky barrier ultraviolet photodetectors","volume":"47","author":"Teke","year":"2003","journal-title":"Solid-State Electron."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"4248","DOI":"10.1002\/adma.201102306","article-title":"Two-dimensional nanocrystals produced by exfoliation of Ti3AlC2","volume":"23","author":"Naguib","year":"2011","journal-title":"Adv. Mater."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"16098","DOI":"10.1038\/natrevmats.2016.98","article-title":"2D metal carbides and nitrides (MXenes) for energy storage","volume":"2","author":"Anasori","year":"2017","journal-title":"Nat. Rev. Mater."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1038\/s41377-021-00619-1","article-title":"MXene-GaN van der Waals metal-semiconductor junctions for high performance multiple quantum well photodetectors","volume":"10","author":"Luo","year":"2021","journal-title":"Light Sci. Appl."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2101059","DOI":"10.1002\/adma.202101059","article-title":"Self-powered MXene\/GaN van der Waals heterojunction ultraviolet photodiodes with superhigh efficiency and stable current outputs","volume":"33","author":"Song","year":"2021","journal-title":"Adv. Mater."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"59567","DOI":"10.1021\/acsami.4c13225","article-title":"Engineering of interface barrier in hybrid MXene\/GaN heterostructures for Schottky diode applications","volume":"16","author":"Majchrzak","year":"2024","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2554","DOI":"10.1364\/AO.553364","article-title":"High-performance self-powered ultraviolet Ti3C2Tx\/GaN Schottky photodiode with an interdigitated electrode","volume":"64","author":"Zhang","year":"2025","journal-title":"Appl. Opt."},{"key":"ref_12","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_13","doi-asserted-by":"crossref","first-page":"18857","DOI":"10.1021\/acsami.8b01194","article-title":"Self-assembled UV photodetector made by direct epitaxial GaN growth on graphene","volume":"10","author":"Journot","year":"2018","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"11965","DOI":"10.1021\/acsami.9b22651","article-title":"Ultrahigh sensitivity graphene\/nanoporous GaN ultraviolet photodetectors","volume":"12","author":"Li","year":"2020","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1007\/s12274-018-2200-z","article-title":"In-situ fabrication of PtSe2\/GaN heterojunction for a self-powered deep-ultraviolet photodetector","volume":"12","author":"Zhuo","year":"2019","journal-title":"Nano Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"6590","DOI":"10.1021\/acs.chemmater.9b00414","article-title":"Surface termination dependent work function and electronic properties of Ti3C2Tx MXene","volume":"31","author":"Schultz","year":"2019","journal-title":"Chem. Mater."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1016\/j.surfrep.2017.05.001","article-title":"The fundamental surface science of wurtzite gallium nitride","volume":"72","author":"Bermudez","year":"2017","journal-title":"Surf. Sci. Rep."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1804779","DOI":"10.1002\/adma.201804779","article-title":"Electronic and optical properties of 2D transition metal carbides and nitrides (MXenes)","volume":"30","author":"Hantanasirisakul","year":"2018","journal-title":"Adv. Mater."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"225303","DOI":"10.1088\/0953-8984\/24\/22\/225303","article-title":"Back-to-back Schottky diodes: The generalization of the diode theory in analysis and extraction of electrical parameters of nanodevices","volume":"24","author":"Chiquito","year":"2012","journal-title":"J. Phys. Condens. Matter"},{"key":"ref_20","unstructured":"(2026, September 18). X-Ray Photoelectron Spectroscopy Database, Standard Reference Database 20, Available online: https:\/\/srdata.nist.gov\/xps\/."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1016\/j.mattod.2015.06.001","article-title":"New concept ultraviolet photodetectors","volume":"18","author":"Chen","year":"2015","journal-title":"Mater. 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