{"title":"Impact of Surrounding Environment on Hot-Exciton Based Organic Emitters for TADF Applications","authors":"Jesni M. Jacob, Dr. Mahesh Kumar Ravva","doi":"10.1002/cptc.202400073","DOIUrl":null,"url":null,"abstract":"<p>Understanding thermally activated delayed fluorescence (TADF) in solid-state environments is crucial for practical applications. However, limited research focuses on how the medium affects TADF properties of hot-exciton-based emitters. In our study, we calculated and compared reverse intersystem crossing, radiative, and non-radiative decay rates of TADF emitters in gas, solvent, and solid phases. The designed emitters have a donor-acceptor-donor (D-A-D) structure, with donors such as triphenylamine (TPA) and diphenylamine thiophene (ThPA), combined with acceptors such as benzothiadiazole (BT), pyridine thiadiazole (PT) and thiadiazolobenzopyridine (NPT). We model the solvent and solid phases with the polarizable continuum model (PCM) and quantum mechanical/molecular mechanics (QM/MM) methods, respectively. Using density functional theory (DFT) and time-dependent DFT, we analyze how TADF emitters′ geometrical, electronic, and excited-state properties vary in these phases. Our results show that the solid-state environment significantly influences the geometry and TADF properties of emitters. In the presence of solid medium, our study indicates that non-radiative decay rates tend to be slower. On the other hand, radiative emission rates were found to be less influenced by the properties of the surrounding medium. Overall, our study connects emitter chemical structure and the surrounding environment‘s impact on excited-state characteristics and photochemical properties.</p>","PeriodicalId":10108,"journal":{"name":"ChemPhotoChem","volume":"8 9","pages":""},"PeriodicalIF":3.0000,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ChemPhotoChem","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/cptc.202400073","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Understanding thermally activated delayed fluorescence (TADF) in solid-state environments is crucial for practical applications. However, limited research focuses on how the medium affects TADF properties of hot-exciton-based emitters. In our study, we calculated and compared reverse intersystem crossing, radiative, and non-radiative decay rates of TADF emitters in gas, solvent, and solid phases. The designed emitters have a donor-acceptor-donor (D-A-D) structure, with donors such as triphenylamine (TPA) and diphenylamine thiophene (ThPA), combined with acceptors such as benzothiadiazole (BT), pyridine thiadiazole (PT) and thiadiazolobenzopyridine (NPT). We model the solvent and solid phases with the polarizable continuum model (PCM) and quantum mechanical/molecular mechanics (QM/MM) methods, respectively. Using density functional theory (DFT) and time-dependent DFT, we analyze how TADF emitters′ geometrical, electronic, and excited-state properties vary in these phases. Our results show that the solid-state environment significantly influences the geometry and TADF properties of emitters. In the presence of solid medium, our study indicates that non-radiative decay rates tend to be slower. On the other hand, radiative emission rates were found to be less influenced by the properties of the surrounding medium. Overall, our study connects emitter chemical structure and the surrounding environment‘s impact on excited-state characteristics and photochemical properties.