{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:20:37Z","timestamp":1760235637432,"version":"build-2065373602"},"reference-count":33,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2021,9,13]],"date-time":"2021-09-13T00:00:00Z","timestamp":1631491200000},"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":["61505015, 21801028, 11704050"],"award-info":[{"award-number":["61505015, 21801028, 11704050"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004829","name":"Department of Science and Technology of Sichuan Province","doi-asserted-by":"publisher","award":["2019YJ0358, 2017FZ0085, 2020YFH0104"],"award-info":[{"award-number":["2019YJ0358, 2017FZ0085, 2020YFH0104"]}],"id":[{"id":"10.13039\/501100004829","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012226","name":"Fundamental Research Funds for the Central Universities","doi-asserted-by":"publisher","award":["YJ201952"],"award-info":[{"award-number":["YJ201952"]}],"id":[{"id":"10.13039\/501100012226","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Department of Human Resources and Social Security of Sichuan Province","award":["2019Z226"],"award-info":[{"award-number":["2019Z226"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The realization of a deep-blue-emitting exciplex system is a herculean task in the field of organic light-emitting diodes (OLEDs) on account of a large red-shifted and broadened exciplex emission spectrum in comparison to those of the corresponding single compounds. Herein, 2,5,8-tris(di(4-fluorophenyl)amine)-1,3,4,6,7,9,9b-heptaazaphenalene (HAP-3FDPA) was designed as an electron acceptor by integrating three bis(4-fluorophenyl)amine groups into a heptazine core, while 1,3-di(9H-carbazol-9-yl)benzene (mCP) possessing two electron-donating carbazole moieties was chosen as the electron donor. Excitingly, the exciplex system of 8 wt% HAP-3FDPA:mCP exhibited deep-blue emission and a high photoluminescence quantum yield of 53.2%. More importantly, an OLED containing this exciplex system as an emitting layer showed deep-blue emission with Commission Internationale de l\u2019Eclairage coordinates of (0.16, 0.12), a peak luminance of 15,148 cd m\u22122, and a rather high maximum external quantum efficiency of 10.2% along with a low roll-off. This study not only reports an efficient exciplex-based deep-blue emitter but also presents a feasible pathway to construct highly efficient deep-blue OLEDs based on exciplex systems.<\/jats:p>","DOI":"10.3390\/molecules26185568","type":"journal-article","created":{"date-parts":[[2021,9,13]],"date-time":"2021-09-13T23:32:23Z","timestamp":1631575943000},"page":"5568","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Efficient Exciplex-Based Deep-Blue Organic Light-Emitting Diodes Employing a Bis(4-fluorophenyl)amine-Substituted Heptazine Acceptor"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1558-8623","authenticated-orcid":false,"given":"Jie","family":"Li","sequence":"first","affiliation":[{"name":"College of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Heqi","family":"Gong","sequence":"additional","affiliation":[{"name":"College of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jincheng","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hui","family":"Liu","sequence":"additional","affiliation":[{"name":"College of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Li","family":"Tao","sequence":"additional","affiliation":[{"name":"College of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yanqing","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qiang","family":"Guo","sequence":"additional","affiliation":[{"name":"College of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,9,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"234","DOI":"10.1038\/nature11687","article-title":"Highly efficient organic light-emitting diodes from delayed fluorescence","volume":"492","author":"Uoyama","year":"2012","journal-title":"Nature"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1499","DOI":"10.1002\/tcr.201800136","article-title":"Molecular design tactics for highly efficient thermally activated delayed fluorescence emitters for organic light emitting diodes","volume":"19","author":"Konidena","year":"2019","journal-title":"Chem. Rec."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1611","DOI":"10.1002\/tcr.201800148","article-title":"High performance thermally activated delayed fluorescence sensitized organic light-emitting diodes","volume":"19","author":"Cai","year":"2019","journal-title":"Chem. Rec."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1765","DOI":"10.1038\/s41467-020-15558-5","article-title":"Nanosecond-time-scale delayed fluorescence molecule for deep-blue oleds with small efficiency rolloff","volume":"11","author":"Kim","year":"2020","journal-title":"Nat. Commun."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2003885","DOI":"10.1002\/adma.202003885","article-title":"Highly efficient thermally activated delayed fluorescence via an unconjugated donor-acceptor system realizing eqe of over 30%","volume":"32","author":"Peng","year":"2020","journal-title":"Adv. Mater."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"339","DOI":"10.1039\/C5CC07999C","article-title":"Highly efficient and color tunable thermally activated delayed fluorescent emitters using a \u201ctwin emitter\u201d molecular design","volume":"52","author":"Kim","year":"2016","journal-title":"Chem. Commun."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"28810","DOI":"10.1021\/acsami.7b07826","article-title":"Toward efficient and metal-free emissive devices: A solution processed host guest light-emitting electrochemical cell featuring thermally activated delayed fluorescence","volume":"9","author":"Lundberg","year":"2017","journal-title":"ACS Appl. Mater. Inter."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"725","DOI":"10.3389\/fchem.2020.00725","article-title":"Recent advances in thermally activated delayed fluorescent polymer-molecular designing strategies","volume":"8","author":"Yin","year":"2020","journal-title":"Front. Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"083302","DOI":"10.1063\/1.3558906","article-title":"Efficient up-conversion of triplet excitons into a singlet state and its application for organic light emitting diodes","volume":"98","author":"Endo","year":"2011","journal-title":"Appl. Phys. Lett."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"326","DOI":"10.1038\/nphoton.2014.12","article-title":"Efficient blue organic light-emitting diodes employing thermally activated delayed fluorescence","volume":"8","author":"Zhang","year":"2014","journal-title":"Nat. Photonics"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"4264","DOI":"10.1039\/C6SC00542J","article-title":"\u201cRate-limited effect\u201d of reverse intersystem crossing process: The key for tuning thermally activated delayed fluorescence lifetime and efficiency roll-off of organic light emitting diodes","volume":"7","author":"Cai","year":"2016","journal-title":"Chem. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1002\/adma.201605444","article-title":"Purely organic thermally activated delayed fluorescence materials for organic light-emitting diodes","volume":"29","author":"Wong","year":"2017","journal-title":"Adv. Mater."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"528","DOI":"10.1039\/D0TC04465B","article-title":"High efficiency and long lifetime orange-red thermally activated delayed fluorescent organic light emitting diodes by donor and acceptor engineering","volume":"9","author":"Kothavale","year":"2021","journal-title":"J. Mater. Chem. C"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"013301","DOI":"10.1063\/1.4887346","article-title":"Thermally activated delayed fluorescence from 3n\u03c0* to 1n\u03c0* up-conversion and its application to organic light-emitting diodes","volume":"105","author":"Li","year":"2014","journal-title":"Appl. Phys. Lett."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"693813","DOI":"10.3389\/fchem.2021.693813","article-title":"Enhanced electroluminescence based on a pi-conjugated heptazine derivative by exploiting thermally activated delayed fluorescence","volume":"9","author":"Li","year":"2021","journal-title":"Front. Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"253","DOI":"10.1038\/nphoton.2012.31","article-title":"Organic light-emitting diodes employing efficient reverse intersystem crossing for triplet-to-singlet state conversion","volume":"6","author":"Goushi","year":"2012","journal-title":"Nat. Photonics"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"6174","DOI":"10.1039\/C4CC01590H","article-title":"Highly efficient exciplex organic light-emitting diodes incorporating a heptazine derivative as an electron acceptor","volume":"50","author":"Li","year":"2014","journal-title":"Chem. Commun."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2343","DOI":"10.1002\/adfm.201303389","article-title":"Photophysical investigation of the thermally activated delayed emission from films of m-mtdata: Pbd exciplex","volume":"24","author":"Graves","year":"2014","journal-title":"Adv. Funct. Mater."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2378","DOI":"10.1002\/adma.201405062","article-title":"Prediction and design of efficient exciplex emitters for high-efficiency, thermally activated delayed-fluorescence organic light-emitting diodes","volume":"27","author":"Liu","year":"2015","journal-title":"Adv. Mater."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1039\/D0MH01245A","article-title":"Thermally activated delayed fluorescence exciplex emitters for high-performance organic light-emitting diodes","volume":"8","author":"Zhang","year":"2021","journal-title":"Mater. Horiz."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1002\/adfm.200800918","article-title":"Harvesting excitons via two parallel channels for efficient white organic leds with nearly 100% internal quantum efficiency: Fabrication and emission-mechanism analysis","volume":"19","author":"Wang","year":"2009","journal-title":"Adv. Funct. Mater."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3319","DOI":"10.1002\/adma.201300575","article-title":"Highly efficient organic light-emitting diode based on a hidden thermally activated delayed fluorescence channel in a heptazine derivative","volume":"25","author":"Li","year":"2013","journal-title":"Adv. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"21719","DOI":"10.1039\/C8TA05430D","article-title":"Emergence of s-heptazines: From trichloro-s-heptazine building blocks to functional materials","volume":"6","author":"Kumar","year":"2018","journal-title":"J. Mater. Chem. A"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2515","DOI":"10.1021\/acs.chemrev.0c00955","article-title":"State of the art in the preparation and properties of molecular monomeric s-heptazines: Syntheses, characteristics, and functional applications","volume":"121","author":"Audebert","year":"2021","journal-title":"Chem. Rev."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Li, J., Zhang, J., Gong, H., Tao, L., Wang, Y., and Guo, Q. (2021). Efficient deep-blue electroluminescence employing heptazine-based thermally activated delayed fluorescence. Photonics, 8.","DOI":"10.3390\/photonics8080293"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"717569","DOI":"10.3389\/fchem.2021.717569","article-title":"Heptazine-based \u03c0-conjugated materials for light-emitting","volume":"9","author":"Li","year":"2021","journal-title":"Front. Chem."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"6826","DOI":"10.1021\/am402032z","article-title":"Highly efficient bilayer interface exciplex for yellow organic light-emitting diode","volume":"5","author":"Hung","year":"2013","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/j.orgel.2016.08.001","article-title":"Thermally activated delayed-fluorescence organic light-emitting diodes based on exciplex emitter with high efficiency and low roll-off","volume":"38","author":"Lin","year":"2016","journal-title":"Org. Electron."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.orgel.2016.09.020","article-title":"High-performance red organic light-emitting devices based on an exciplex system with thermally activated delayed fluorescence characteristic","volume":"39","author":"Yuan","year":"2016","journal-title":"Org. Electron."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"18259","DOI":"10.1021\/acs.jpcc.6b05198","article-title":"Investigation of the mechanisms giving rise to tadf in exciplex states","volume":"120","author":"Santos","year":"2016","journal-title":"J. Phys. Chem. C"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2002","DOI":"10.1002\/adfm.201505014","article-title":"Novel strategy to develop exciplex emitters for high-performance oleds by employing thermally activated delayed fluorescence materials","volume":"26","author":"Liu","year":"2016","journal-title":"Adv. Funct. Mater."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"19294","DOI":"10.1021\/acsami.9b04365","article-title":"Exciplex organic light-emitting diodes with nearly 20% external quantum efficiency: Effect of intermolecular steric hindrance between the donor and acceptor pair","volume":"11","author":"Wu","year":"2019","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"953","DOI":"10.1021\/cr050143+","article-title":"Charge carrier transporting molecular materials and their applications in devices","volume":"107","author":"Shirota","year":"2007","journal-title":"Chem. Rev."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/26\/18\/5568\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:02:07Z","timestamp":1760166127000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/26\/18\/5568"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,9,13]]},"references-count":33,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2021,9]]}},"alternative-id":["molecules26185568"],"URL":"https:\/\/doi.org\/10.3390\/molecules26185568","relation":{},"ISSN":["1420-3049"],"issn-type":[{"type":"electronic","value":"1420-3049"}],"subject":[],"published":{"date-parts":[[2021,9,13]]}}}