{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T01:37:37Z","timestamp":1792805857306,"version":"4.5.0"},"reference-count":46,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2020,9,9]],"date-time":"2020-09-09T00:00:00Z","timestamp":1599609600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["No.21903017, No.21907063 and No.21503066"],"award-info":[{"award-number":["No.21903017, No.21907063 and No.21503066"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003453","name":"Natural Science Foundation of Guangdong Province","doi-asserted-by":"publisher","award":["2019A1515010783"],"award-info":[{"award-number":["2019A1515010783"]}],"id":[{"id":"10.13039\/501100003453","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Guangzhou Science and Technology Plan Project","award":["202001010002"],"award-info":[{"award-number":["202001010002"]}]},{"name":"Young Talents Program of Guangzhou University","award":["RQ2020080"],"award-info":[{"award-number":["RQ2020080"]}],"id":[{"id":"https:\/\/ror.org\/05ar8rn06","id-type":"ROR","asserted-by":"crossref"}]},{"name":"General Program of Chongqing Natural Science Foundation","award":["cstc2019jcyj-msxmX0874"],"award-info":[{"award-number":["cstc2019jcyj-msxmX0874"]}]},{"DOI":"10.13039\/100007421","name":"Li Ka Shing Foundation","doi-asserted-by":"publisher","award":["project LD0101"],"award-info":[{"award-number":["project LD0101"]}],"id":[{"id":"10.13039\/100007421","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Y6 is a new type of non-fullerene acceptor, which has led to power conversion efficiencies of single-junction polymer solar cells over 17% when combined with a careful choice of polymeric donors. However, the excited state characteristics of Y6, which is closely correlated with its opto-electronic applications, are not clear yet. In this work, we studied the excited state properties of the Y6 solution and Y6 film, by using steady-state and time-resolved spectroscopies as well as time-dependent density functional theory (TD-DFT) calculations. UV-Vis absorption and fluorescence simulation, natural transition orbitals (NTOs) and hole-electron distribution analysis of Y6 solution were performed for understanding the excitation properties of Y6 by using TD-DFT calculations. The lifetimes of the lowest singlet excited state in Y6 solution and film were estimated to be 0.98 and 0.8 ns, respectively. Combining the exciton lifetime and photoluminescence (PL) quantum yield, the intrinsic radiative decay lifetimes of Y6 in the solution and film were estimated, which were 1.3 and 10.5 ns for the Y6 solution and film, respectively. Long exciton lifetime (~0.8 ns) and intrinsic radiative decay lifetime (~10.5 ns) of Y6 film enable Y6 to be a good acceptor material for the application of polymer solar cells.<\/jats:p>","DOI":"10.3390\/molecules25184118","type":"journal-article","created":{"date-parts":[[2020,9,10]],"date-time":"2020-09-10T22:58:01Z","timestamp":1599778681000},"page":"4118","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":64,"title":["An Insight into the Excitation States of Small Molecular Semiconductor Y6"],"prefix":"10.3390","volume":"25","author":[{"given":"Xianshao","family":"Zou","sequence":"first","affiliation":[{"name":"School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, China"},{"name":"Division of Chemical Physics, Lund University, 22100 Lund, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guanzhao","family":"Wen","sequence":"additional","affiliation":[{"name":"School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rong","family":"Hu","sequence":"additional","affiliation":[{"name":"National Research Base of Co-Innovation Center for Micro\/Nano Optoelectronic Materials and Devices, Chongqing University of Arts and Sciences, Chongqing 402160, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0901-441X","authenticated-orcid":false,"given":"Geng","family":"Dong","sequence":"additional","affiliation":[{"name":"Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, China"},{"name":"Medical Informatics Research Center, Shantou University Medical College, Shantou 515041, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chengyun","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Physics and Materials Science, Guangzhou University, Guangzhou 510006, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hao","family":"Huang","sequence":"additional","affiliation":[{"name":"Hebei Key Lab of Optic-Electronic Information and Materials, College of Physics Science and Technology, Hebei University, Baoding 071002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei","family":"Dang","sequence":"additional","affiliation":[{"name":"Hebei Key Lab of Optic-Electronic Information and Materials, College of Physics Science and Technology, Hebei University, Baoding 071002, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,9,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1789","DOI":"10.1126\/science.270.5243.1789","article-title":"Polymer photovoltaic cells: Enhanced efficiencies via a network of internal donor-acceptor heterojunctions","volume":"270","author":"Yu","year":"1995","journal-title":"Science"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"498","DOI":"10.1038\/376498a0","article-title":"Efficient photodiodes from interpenetrating polymer networks","volume":"376","author":"Halls","year":"1995","journal-title":"Nature"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"aad4424","DOI":"10.1126\/science.aad4424","article-title":"Photovoltaic materials: Present efficiencies and future challenges","volume":"352","author":"Polman","year":"2016","journal-title":"Science"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"7765","DOI":"10.1039\/D0TA01340D","article-title":"Significantly enhanced electron transport of a nonfullerene acceptor in a blend film with a high hole mobility polymer of high molecular weight: Thick-film nonfullerene polymer solar cells showing a high fill factor","volume":"8","author":"Wang","year":"2020","journal-title":"J. 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