{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T15:02:50Z","timestamp":1787238170432,"version":"build-2736575974"},"reference-count":42,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2025,8,11]],"date-time":"2025-08-11T00:00:00Z","timestamp":1754870400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Union\u2014NextGenerationEU","award":["BG-RRP-2.004-0002"],"award-info":[{"award-number":["BG-RRP-2.004-0002"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>The main goal of this study was to investigate the properties of ZnO thin films, including pure films and those doped with indium (up to 8 mol%) that was deposited using a spray pyrolysis technique on glass and silicon substrates in order to prepare the position-sensitive structure, Si-SiO2-ZnO:In. To this aim, the present work is focused on investigating the effect of indium concentration on the morphology, structure, and optical properties of the films. X-ray diffraction (XRD) analysis reveals a wurtzite polycrystalline structure. Scanning electron microscopy (SEM) images display a smooth and uniform surface characterized by closely packed nanocrystalline clusters. As the indium concentration rises to 8 mol%, the number of nuclei grows, resulting in uniformly distributed grains across the entire substrate surface. The estimated root mean square (RMS) roughness values for the thin films undoped and doped with 3 mol%, 5 mol%, and 8 mol% of ZnO measured using AFM are 6.13, 9.64, and 13.76 nm, respectively. The increase in indium concentration leads to a slight decrease in film transmittance. The measured LPV photosensitivity of about 44 mV\/mm confirms the potential use of these thin films in practical applications.<\/jats:p>","DOI":"10.3390\/ma18163744","type":"journal-article","created":{"date-parts":[[2025,8,11]],"date-time":"2025-08-11T09:04:53Z","timestamp":1754903093000},"page":"3744","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Indium-Doped ZnO Thin Films Obtained Using Spray Pyrolysis for Position-Sensitive Photodetection"],"prefix":"10.3390","volume":"18","author":[{"given":"Pavlina","family":"Bancheva-Koleva","sequence":"first","affiliation":[{"name":"Physics Department, University of Chemical Technology and Metallurgy, 8 Kliment Ohridski Blvd., 1756 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Veselin","family":"Zhelev","sequence":"additional","affiliation":[{"name":"Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, Akad. G. Bonchev Str. Bl. 10, 1000 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Plamen","family":"Petkov","sequence":"additional","affiliation":[{"name":"Physics Department, University of Chemical Technology and Metallurgy, 8 Kliment Ohridski Blvd., 1756 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1224-0103","authenticated-orcid":false,"given":"Tamara","family":"Petkova","sequence":"additional","affiliation":[{"name":"Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, Akad. G. Bonchev Str. Bl. 10, 1000 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,8,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"575","DOI":"10.1016\/j.jallcom.2009.04.139","article-title":"Effect of annealing temperature on the structure and optical properties of In-doped ZnO thin films","volume":"484","author":"Peng","year":"2009","journal-title":"J. Alloys Compd."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3875","DOI":"10.1016\/j.ceramint.2012.01.039","article-title":"The role of substrate temperature on the properties of nanocrystalline Mo doped ZnO thin films by spray pyrolysis","volume":"38","author":"Swapna","year":"2012","journal-title":"Ceram. Int."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"252","DOI":"10.1007\/s00339-022-05377-4","article-title":"Synthesis and investigating effect of tellurium-doping on physical propetryies of zinc oxide thin films by spray pyrolysis","volume":"128","author":"Rouhi","year":"2022","journal-title":"Appl. Phys. A"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"24324","DOI":"10.1016\/j.ceramint.2019.08.147","article-title":"Influence of nitrogen dopant source on the structural, photoluminescence and electrical properties of ZnO thin films deposited by pulsed spray pyrolysis","volume":"45","author":"KaniAmuthan","year":"2019","journal-title":"Ceram. Int."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"148","DOI":"10.1016\/j.matpr.2022.01.053","article-title":"Spray pyrolysis deposited aluminium-indium zinc oxide thin films and study their electrical and photoluminescence properties","volume":"55","author":"Ganesh","year":"2022","journal-title":"Mater. Today Proc."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"316","DOI":"10.1016\/j.tsf.2014.11.092","article-title":"Growth and electro-optical properties of Ga-doped ZnO films prepared by aerosol assisted chemical vapour deposition","volume":"584","author":"Chen","year":"2015","journal-title":"Thin Solid Film."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1016\/j.spmi.2015.03.028","article-title":"Effect on Er concentration on surface and optical properties of K doped ZnO sol-gel thin films","volume":"83","author":"Vettumperumal","year":"2015","journal-title":"Superlattices Microstruct."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"19473","DOI":"10.1016\/j.ceramint.2019.06.204","article-title":"Optical transmittance and photoluminescence of fluorine-doped zinc oxide thin films prepared by ultrasonic spray pyrolysis","volume":"45","author":"Hegazy","year":"2019","journal-title":"Ceram. Int."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"839","DOI":"10.1016\/j.apsusc.2018.01.107","article-title":"Influence of crystallographic polarity on the opto-electrical properties of polycrystalline ZnO thin films deposited by magnetron sputtering","volume":"439","author":"Makino","year":"2018","journal-title":"Appl. Surf. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"651","DOI":"10.1016\/j.rinp.2016.12.029","article-title":"Characterizations of multilayer ZnO thin films deposited by sol-gel spin coating technique","volume":"7","author":"Khan","year":"2017","journal-title":"Results Phys."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"100504","DOI":"10.1016\/j.surfin.2020.100504","article-title":"Structural, optical and thermoelectric properties of Al-doped ZnO thin films prepared by spray pyrolysis","volume":"19","author":"Ambedkar","year":"2020","journal-title":"Surf. Interfaces"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"10066","DOI":"10.1016\/j.ceramint.2016.03.110","article-title":"Effect of gallium doping on the structural, optical and electrical properties of zinc oxide thin films prepared by spray pyrolysis","volume":"42","author":"Muchuweni","year":"2016","journal-title":"Ceram. Interfaces"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"106511","DOI":"10.1016\/j.spmi.2020.106511","article-title":"Synergetic effects of aluminium and indium dopants in the physical properties of ZnO thin films via spray pyrolysis","volume":"142","author":"Mahesh","year":"2020","journal-title":"Superlattices Microstruct."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1313","DOI":"10.1016\/j.ijleo.2018.01.024","article-title":"Enhancement of visible luminescence and photocatalytic activity of ZnO thin films via Cu doping","volume":"158","author":"Narayanan","year":"2018","journal-title":"Optik"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1016\/j.apsusc.2019.07.091","article-title":"Enhanced UV light induced photocatalytic degradation of methyl orange by Fe doped spray pyrolysis deposited ZnO thin films","volume":"494","author":"Sree","year":"2019","journal-title":"Appl. Surf. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"100965","DOI":"10.1016\/j.surfin.2021.100965","article-title":"Fabrication of In doped ZnO thin films by spray pyrolysis as photoanode in DSSCs","volume":"23","author":"Dhamodharan","year":"2021","journal-title":"Surf. Interfaces"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Korotchenkov, G., Brinzari, V., and Ham, M.-H. (2018). In2O3-based thermoelectric materials: The stae of the art and the role of surface state in the improvement of the efficiency of thermoelectric conversion. Crystals, 8.","DOI":"10.3390\/cryst8010014"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2957","DOI":"10.1016\/j.jeurceramsoc.2011.07.006","article-title":"Preparation of Ni-doped ZnO ceramics for thermoelectric applications","volume":"31","author":"Colder","year":"2011","journal-title":"J. Eur. Ceram. Soc."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1016\/j.jallcom.2007.01.080","article-title":"Improvement of thermoelectric properties with the addition of Sb to ZnO","volume":"455","author":"Park","year":"2008","journal-title":"J. Alloys Compd."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"488","DOI":"10.1016\/j.solidstatesciences.2012.01.019","article-title":"Synthesis, magnetic properties and X-ray analysis of Zn0.97X0.03O nanoparyicles (X = Mn, Ni and Co) using Scherrer and size train plot methods","volume":"14","author":"Zak","year":"2012","journal-title":"Solid State Sci."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1016\/j.jallcom.2013.01.184","article-title":"Influence of K-doping on the optical properties of ZnO thin films grown by chemical bath deposition method","volume":"562","author":"Shanmuganathan","year":"2013","journal-title":"J. Alloys Compd."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jphotobiol.2013.01.003","article-title":"Photoelectrochemical properties of highly mobilized Li-doped ZnO thin films","volume":"120","author":"Shinde","year":"2013","journal-title":"J. Photochem. Photobiol. B Biol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"399","DOI":"10.1186\/1556-276X-9-399","article-title":"Optical properties of ZnO\/BaCO3 nanocomposites in UV and visible regions","volume":"9","author":"Zak","year":"2014","journal-title":"Nanoscales Res. Lett."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"7267","DOI":"10.1016\/j.jallcom.2011.04.058","article-title":"In doped thin films","volume":"509","author":"Hafdallah","year":"2011","journal-title":"J. Alloys Compd."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Bancheva-Koleva, P., Zhelev, V., Petkov, P., and Petkova, T. (2024). Molybdenum-doped ZnO thin films obtained by spray pyrolysis. Materials, 17.","DOI":"10.3390\/ma17092164"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"011308","DOI":"10.1063\/5.0175150","article-title":"Grain boundaries in polycrystalline materials for energy applications: First principles modeling and electron microscopy","volume":"11","author":"Quirk","year":"2024","journal-title":"Appl. Phys. Rev."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.optmat.2015.08.021","article-title":"Impact of low temperature annealing on structural, optical, electrical and morphological properties of ZnO thin films grown by RF sputtering for photovoltaic applications","volume":"49","author":"Purohit","year":"2015","journal-title":"Opt. Mater."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"6308","DOI":"10.1016\/j.apsusc.2009.02.007","article-title":"Microstructures, optical and electrical properties of In-doped ZnO thin films prepared by sol-gel method","volume":"255","author":"Chen","year":"2009","journal-title":"Appl. Surf. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1006","DOI":"10.1016\/j.apsusc.2013.07.060","article-title":"Nanostructured ZnO films with various morphologies prepared by ultrasonis spray pyrolysis and its growing process","volume":"283","author":"Ma","year":"2013","journal-title":"Appl. Surf. Sci."},{"key":"ref_30","first-page":"4796","article-title":"Structural, optical and electrical characteristics of nanostructured ZnO thin films with various thicknesses deposited by RF magnetron sputtering","volume":"2320","author":"Kumar","year":"2013","journal-title":"Res. J. Phys. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"110562","DOI":"10.1016\/j.vacuum.2021.110562","article-title":"Activation energy and its fluctuations at grain boundaries of Er3+:BaTiO3 perovskite this films: Effect of doping concentration and annealing temperature","volume":"194","author":"Clabel","year":"2021","journal-title":"Vacuum"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"5791","DOI":"10.1016\/j.apsusc.2008.03.080","article-title":"The crystallization and physical properties of Al-doped ZnO nanoparticles","volume":"254","author":"Chen","year":"2008","journal-title":"Appl. Surf. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1622","DOI":"10.1111\/j.1151-2916.1998.tb02524.x","article-title":"Sol-Gel Preparation of Transparent and Conductive Aluminum-Doped Zinc Oxide Films with Highly Preferential Crystal Orientation","volume":"81","author":"Ohyama","year":"1998","journal-title":"Am. Ceram. Soc."},{"key":"ref_34","unstructured":"Cullity, B.D. (1978). The Elements of X-Ray Diffraction, Addison-Wesley, Reading."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1016\/j.tsf.2005.04.043","article-title":"Indium-doped ZnO thin films deposited by sol-gel technique","volume":"490","author":"Maldonado","year":"2005","journal-title":"Solid Film."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"7212","DOI":"10.1016\/j.apsusc.2009.03.065","article-title":"Highly oriented (100) ZnO thin films by spray pyrolysis","volume":"255","author":"Rao","year":"2009","journal-title":"Appl. Surf. Sci."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Jiles, D. (1994). Introduction to the Electronic Properties of Materials, Chapman and Hall.","DOI":"10.1007\/978-1-4615-2582-0"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"632","DOI":"10.1103\/PhysRev.93.632","article-title":"Anomalous optical absorption limit in InSb","volume":"93","author":"Burstein","year":"1954","journal-title":"Phys. Rev."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"3019","DOI":"10.1016\/j.jcrysgro.2008.03.004","article-title":"Band gap engineering of ZnO thin films by In2O3 incorporation","volume":"310","author":"Gupta","year":"2008","journal-title":"J. Cryst. Growth"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"102146","DOI":"10.1016\/j.rinp.2019.02.082","article-title":"Investigations of structural and optical properties of zinc oxide thin films growth on various substrates","volume":"13","author":"Ribut","year":"2019","journal-title":"Results Phys."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.tsf.2018.03.009","article-title":"As-doped SnO2 thin films for use as large area position sensitive photodetector","volume":"653","author":"Zhelev","year":"2018","journal-title":"Thin Solid Film."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Zhelev, V., Petkov, P., Avdeev, G., Lilova, V., and Petkova, T. (2020). Study of In2O3 thin films doped with As as active layer in position sensitive structures. Nanoscience and Nanotechnology in Security and Protection Against CBRN Threats, Springer Nature. NATO Science for Peace and Security Series B: Physics and Biophysics.","DOI":"10.1007\/978-94-024-2018-0_10"}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/16\/3744\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:27:55Z","timestamp":1760034475000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/16\/3744"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8,11]]},"references-count":42,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2025,8]]}},"alternative-id":["ma18163744"],"URL":"https:\/\/doi.org\/10.3390\/ma18163744","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,8,11]]}}}