{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T11:02:56Z","timestamp":1774522976230,"version":"3.50.1"},"reference-count":45,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2020,10,7]],"date-time":"2020-10-07T00:00:00Z","timestamp":1602028800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea","doi-asserted-by":"publisher","award":["NRF-2018R1A2A1A05023126"],"award-info":[{"award-number":["NRF-2018R1A2A1A05023126"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Tin sulfide (SnS) is known for its effective gas-detecting ability at low temperatures. However, the development of a portable and flexible SnS sensor is hindered by its high resistance, low response, and long recovery time. Like other chalcogenides, the electronic and gas-sensing properties of SnS strongly depend on its surface defects. Therefore, understanding the effects of its surface defects on its electronic and gas-sensing properties is a key factor in developing low-temperature SnS gas sensors. Herein, using thin SnS films annealed at different temperatures, we demonstrate that SnS exhibits n-type semiconducting behavior upon the appearance of S vacancies. Furthermore, the presence of S vacancies imparts the n-type SnS sensor with better sensing performance under UV illumination at room temperature (25 \u00b0C) than that of a p-type SnS sensor. These results are thoroughly investigated using various experimental analysis techniques and theoretical calculations using density functional theory. In addition, n-type SnS deposited on a polyimide substrate can be used to fabricate high-stability flexible sensors, which can be further developed for real applications.<\/jats:p>","DOI":"10.3390\/s20195701","type":"journal-article","created":{"date-parts":[[2020,10,7]],"date-time":"2020-10-07T09:12:58Z","timestamp":1602061978000},"page":"5701","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":23,"title":["Defect-Induced Gas-Sensing Properties of a Flexible SnS Sensor under UV Illumination at Room Temperature"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0652-7009","authenticated-orcid":false,"given":"Nguyen","family":"Manh Hung","sequence":"first","affiliation":[{"name":"Department of Materials Science and Engineering, Chungnam National University, Daejeon 34134, Korea"},{"name":"Department of Materials Science and Engineering, Le Quy Don Technical University, Hanoi 100000, Vietnam"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chuong V.","family":"Nguyen","sequence":"additional","affiliation":[{"name":"Department of Materials Science and Engineering, Le Quy Don Technical University, Hanoi 100000, Vietnam"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vinaya Kumar","family":"Arepalli","sequence":"additional","affiliation":[{"name":"Department of Energy Convergence Engineering, Cheongju University, Cheongju 28503, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jeha","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Energy Convergence Engineering, Cheongju University, Cheongju 28503, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5877-0724","authenticated-orcid":false,"given":"Nguyen","family":"Duc Chinh","sequence":"additional","affiliation":[{"name":"Department of Materials Science and Engineering, Chungnam National University, Daejeon 34134, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9420-210X","authenticated-orcid":false,"given":"Tien Dai","family":"Nguyen","sequence":"additional","affiliation":[{"name":"Institute of Theoretical and Applied Research, Duy Tan University, Hanoi 100000, Vietnam"},{"name":"Faculty of Natural Sciences, Duy Tan University, Da Nang 550000, Vietnam"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dong-Bum","family":"Seo","sequence":"additional","affiliation":[{"name":"Department of Materials Science and Engineering, Chungnam National University, Daejeon 34134, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5488-7159","authenticated-orcid":false,"given":"Eui-Tae","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Materials Science and Engineering, Chungnam National University, Daejeon 34134, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chunjoong","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Materials Science and Engineering, Chungnam National University, Daejeon 34134, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0964-8527","authenticated-orcid":false,"given":"Dojin","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Materials Science and Engineering, Chungnam National University, Daejeon 34134, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,10,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1007\/s11706-015-0279-7","article-title":"Semiconductor metal oxide compounds based gas sensors: A literature review","volume":"9","author":"Patil","year":"2015","journal-title":"Front. Mater. Sci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"314","DOI":"10.1016\/j.jhazmat.2018.06.015","article-title":"Resistance-based H2S gas sensors using metal oxide nanostructures: A review of recent advances","volume":"357","author":"Mirzaei","year":"2018","journal-title":"J. Hazard. Mater."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1016\/j.snb.2014.07.074","article-title":"Nanoscale metal oxide-based heterojunctions for gas sensing: A review","volume":"204","author":"Miller","year":"2014","journal-title":"Sens. Actuators B Chem."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1002\/smll.201101016","article-title":"Fabrication of single-and multilayer MoS2 film-based field-effect transistors for sensing NO at room temperature","volume":"8","author":"Li","year":"2012","journal-title":"Small"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1016\/j.snb.2016.08.163","article-title":"WS2 nanoflakes based selective ammonia sensors at room temperature","volume":"240","author":"Li","year":"2017","journal-title":"Sens. Actuators B Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"9545","DOI":"10.1021\/acsami.6b01485","article-title":"Growth of large-size SnS thin crystals driven by oriented attachment and applications to gas sensors and photodetectors","volume":"8","author":"Wang","year":"2016","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"10313","DOI":"10.1021\/acsnano.5b04343","article-title":"Physisorption-based charge transfer in two-dimensional SnS2 for selective and reversible NO2 gas sensing","volume":"9","author":"Ou","year":"2015","journal-title":"ACS Nano"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"771","DOI":"10.1016\/j.snb.2018.02.060","article-title":"Enhanced room-temperature NH3 gas sensing by 2D SnS2 with sulfur vacancies synthesized by chemical exfoliation","volume":"262","author":"Qin","year":"2018","journal-title":"Sens. Actuators B Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"4642","DOI":"10.1021\/acsanm.0c00649","article-title":"Activating the Basal Plane of Defective SnS2 Nanosheets for NH3 Gas Sensing","volume":"3","author":"Zhang","year":"2020","journal-title":"ACS Appl. Nano Mater."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1016\/j.apsusc.2017.10.167","article-title":"NO-sensing performance of vacancy defective monolayer MoS2 predicted by density function theory","volume":"434","author":"Li","year":"2018","journal-title":"Appl. Surface Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1744","DOI":"10.1021\/acssensors.7b00731","article-title":"UV-activated MoS2 based fast and reversible NO2 sensor at room temperature","volume":"2","author":"Kumar","year":"2017","journal-title":"ACS Sens."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"10045","DOI":"10.1021\/acsnano.8b04620","article-title":"Contact and Noncontact Measurement of Electronic Transport in Individual 2D SnS Colloidal Semiconductor Nanocrystals","volume":"12","author":"Biacchi","year":"2018","journal-title":"ACS Nano"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"4370","DOI":"10.1016\/j.tsf.2010.01.040","article-title":"Optimization of parameters of chemical spray pyrolysis technique to get n and p-type layers of SnS","volume":"518","author":"Sajeesh","year":"2010","journal-title":"Thin Solid Films"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"21556","DOI":"10.1039\/C7RA03004E","article-title":"Two-dimensional SnS nanoflakes: Synthesis and application to acetone and alcohol sensors","volume":"7","author":"Afsar","year":"2017","journal-title":"RSC Adv."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/0040-6090(89)90536-1","article-title":"Chemical deposition of tin (II) sulphide thin films","volume":"173","author":"Ristov","year":"1989","journal-title":"Thin Solid Films"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1016\/j.snb.2018.10.113","article-title":"Adsorption\/desorption kinetics of nitric oxide on zinc oxide nano film sensor enhanced by light irradiation and gold-nanoparticles decoration","volume":"281","author":"Chinh","year":"2019","journal-title":"Sens. Actuators B Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1016\/j.jallcom.2018.11.153","article-title":"UV-light-activated H2S gas sensing by a TiO2 nanoparticulate thin film at room temperature","volume":"778","author":"Chinh","year":"2019","journal-title":"J. Alloy. Compd."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"128001","DOI":"10.1016\/j.snb.2020.128001","article-title":"Rb2CO3-decorated In2O3 nanoparticles for the room-temperature detection of sub-ppm level NO2","volume":"313","author":"Hung","year":"2020","journal-title":"Sens. Actuators B Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2063","DOI":"10.1039\/C5NR07675G","article-title":"Physical vapor deposition synthesis of two-dimensional orthorhombic SnS flakes with strong angle\/temperature-dependent Raman responses","volume":"8","author":"Xia","year":"2016","journal-title":"Nanoscale"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5544","DOI":"10.1021\/acs.cgd.7b01100","article-title":"Deposition of SnS Thin Films from Sn(II) Thioamidate Precursors","volume":"17","author":"Catherall","year":"2017","journal-title":"Crystal Growth Design"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1486","DOI":"10.1039\/b009923f","article-title":"The first single source deposition of tin sulfide coatings on glass: Aerosol-assisted chemical vapour deposition using [Sn(SCHCHS)]","volume":"11","author":"Parkin","year":"2001","journal-title":"J. Mater. Chem."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"266","DOI":"10.1021\/cm301660n","article-title":"Organotin dithiocarbamates: Single-source precursors for tin sulfide thin films by aerosol-assisted chemical vapor deposition (AACVD)","volume":"25","author":"Ramasamy","year":"2013","journal-title":"Chem. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"330","DOI":"10.1016\/j.apsusc.2018.08.115","article-title":"Low-operating temperature NO2 gas sensors based on hybrid two-dimensional SnS2-reduced graphene oxide","volume":"462","author":"Shafiei","year":"2018","journal-title":"Appl. Surface Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"105421","DOI":"10.1039\/C6RA21252B","article-title":"SnS2 nanoflakes for efficient humidity and alcohol sensing at room temperature","volume":"6","author":"Bharatula","year":"2016","journal-title":"RSC Adv."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"438","DOI":"10.1016\/j.cap.2020.01.002","article-title":"Influence of Ag thickness on the structural, optical, and electrical properties of the SnS\/Ag\/SnS trilayer films for solar cell application","volume":"20","author":"Arepalli","year":"2020","journal-title":"Curr. Appl. Phys."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"463","DOI":"10.1016\/j.apsusc.2017.01.113","article-title":"Impact of high temperature and short period annealing on SnS films deposited by E-beam evaporation","volume":"402","author":"Gedi","year":"2017","journal-title":"Appl. Surf. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"153653","DOI":"10.1016\/j.jallcom.2020.153653","article-title":"Structural, optical and photoelectrochemical properties of phase pure SnS and SnS2 thin films prepared by vacuum evaporation method","volume":"822","author":"Sharma","year":"2020","journal-title":"J. Alloys Compd."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"95680","DOI":"10.1039\/C6RA20129F","article-title":"Co-evaporated SnS thin films for visible light photodetector applications","volume":"6","author":"Reddy","year":"2016","journal-title":"RSC Adv."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1820","DOI":"10.1039\/C6NR09022B","article-title":"Tunable UV-visible absorption of SnS2 layered quantum dots produced by liquid phase exfoliation","volume":"9","author":"Fu","year":"2017","journal-title":"Nanoscale"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1312","DOI":"10.1039\/C5TA08214E","article-title":"Electronic and optical properties of single crystal SnS2: An earth-abundant disulfide photocatalyst","volume":"4","author":"Burton","year":"2016","journal-title":"J. Mater. Chem. A"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2325","DOI":"10.1016\/j.materresbull.2013.02.082","article-title":"Phase-controlled synthesis and photocatalytic properties of SnS, SnS2 and SnS\/SnS2 heterostructure nanocrystals","volume":"48","author":"Hu","year":"2013","journal-title":"Mater. Res. Bull."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Mittal, K.L. (2005). Polyimides and Other High Temperature Polymers: Synthesis, Characterization and Applications, CRC Press.","DOI":"10.1201\/b12194"},{"key":"ref_33","unstructured":"Moulder, J.F. (1995). Handbook of X-ray photoelectron spectroscopy, Physical Electron."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"837","DOI":"10.1016\/j.tsf.2011.01.355","article-title":"Physical properties of very thin SnS films deposited by thermal evaporation","volume":"520","author":"Cheng","year":"2011","journal-title":"Thin Solid Films"},{"key":"ref_35","unstructured":"Patnaik, P. (2003). Handbook of Inorganic Chemicals, McGraw-Hill."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"6085","DOI":"10.1039\/C7NR01120B","article-title":"Effects of graphene defects on gas sensing properties towards NO2 detection","volume":"9","author":"Ricciardella","year":"2017","journal-title":"Nanoscale"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1701640","DOI":"10.1002\/admi.201701640","article-title":"Defect-Induced Gas Adsorption on Graphene Transistors","volume":"5","author":"Liu","year":"2018","journal-title":"Adv. Mater. Interfaces"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"688","DOI":"10.1016\/j.snb.2016.01.094","article-title":"Gas sensing properties of defect-induced single-walled carbon nanotubes","volume":"228","author":"Kim","year":"2016","journal-title":"Sens. Actuators B Chem."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.synthmet.2014.01.005","article-title":"Highly sensitive, reproducible, selective and stable CSA-polypyrrole NO2 sensor","volume":"189","author":"Navale","year":"2014","journal-title":"Synth. Metals"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1598","DOI":"10.1016\/j.synthmet.2012.07.002","article-title":"Polypyrrole\u2013ZnO hybrid sensor: Effect of camphor sulfonic acid doping on physical and gas sensing properties","volume":"162","author":"Chougule","year":"2012","journal-title":"Synth. Metals"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1016\/j.matlet.2016.08.010","article-title":"Novel p-n heterojunction-type rGO\/CeO2 bilayer membrane for room-temperature nitrogen dioxide detection","volume":"186","author":"Jiang","year":"2017","journal-title":"Mater. Lett."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"213105","DOI":"10.1063\/1.3432446","article-title":"Flexible room-temperature NO2 gas sensors based on carbon nanotubes\/reduced graphene hybrid films","volume":"96","author":"Jeong","year":"2010","journal-title":"Appl. Phys. Lett."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Pyeon, J.J., Baek, I.-H., Song, Y.G., Kim, G.S., Cho, A.-J., Lee, G.-Y., Han, J.H., Chung, T.-M., Hwang, C.S., and Kang, C.-Y. (2020). Highly sensitive flexible NO2 sensor composed of vertically aligned 2D SnS2 operating at room temperature. J. Mater. Chem. C.","DOI":"10.1039\/D0TC02242J"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"14179","DOI":"10.1021\/acsomega.9b00935","article-title":"High-Performance UV-Assisted NO2 Sensor Based on Chemical Vapor Deposition Graphene at Room Temperature","volume":"4","author":"Yan","year":"2019","journal-title":"ACS Omega"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Hung, N.M., Chinh, N.D., Nguyen, T.D., Kim, E.T., Choi, G., Kim, C., and Kim, D. (2020). Carbon nanotube-metal oxide nanocomposite gas sensing mechanism assessed via NO2 adsorption on n-WO3\/p-MWCNT nanocomposites. Ceram. Int.","DOI":"10.1016\/j.ceramint.2020.08.097"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/19\/5701\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:17:02Z","timestamp":1760177822000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/19\/5701"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,10,7]]},"references-count":45,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2020,10]]}},"alternative-id":["s20195701"],"URL":"https:\/\/doi.org\/10.3390\/s20195701","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,10,7]]}}}