2026-10-13T09:50:39Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34021590 2026-09-29T06:05:00Z category_1 category_146 category_915 category_21 category_24 category_272 category_873 category_39 category_734 category_106 portal_63 item_type_6 month_year_09_2026

Triplet Exciton Convergence toward Charge-Transfer States Enables Long-Wavelength Room-Temperature Phosphorescence from Carbon Dots Guohui Yang (1928113) Fu Qin (6496070) Xu Yu (1625428) Xiaoyue Wang (212345) Xinyu Wang (341591) Jianliang Bai (11139205) Shengyu Qian (25135692) Qian Wang (32718) Pengsong Cui (25135695) Chenyang Liu (1616050) Lili Ren (174380) Biophysics Space Science Physical Sciences not elsewhere classified Biotechnology Evolutionary Biology Environmental Sciences not elsewhere classified Chemical Sciences not elsewhere classified Ecology Biological Sciences not elsewhere classified Science Policy transmission electron microscopy successfully constructed via step hydrothermal method ray photoelectron spectroscopy intrinsic triplet excitons crystal structure analysis cds ), especially new theoretical framework intrinsic energy levels energy charge transfer red phosphorescent ones matrix effects drives temperature phosphorescent cds based phosphorescent materials cds toward ct wavelength phosphorescence generation carbon dots long wavelength phosphorescence emission temperature phosphorescence red phosphorescence energy emission phosphorescent centers cds presents cds driven wavelength phosphorescence theoretical calculations energy triplets wavelength room work proposes using (< traditional regulation substantial challenge study provides rational development r </ pyromellitic acid potential applications key mechanism infrared cd excited states even near design philosophy design approach broad applicability >)- methylbenzylamine Long-wavelength room-temperature phosphorescent carbon dots (CDs), especially the red phosphorescent ones, have garnered significant attention due to their low-energy emission and potential applications. However, the achievement of red phosphorescence in CDs presents a substantial challenge, and the underlying emission mechanism remains largely elusive. This work proposes a construction strategy for long-wavelength phosphorescence of CDs driven by matrix-induced low-energy charge transfer (CT) excited states. By guiding the directional migration and aggregation of intrinsic triplet excitons of CDs toward CT-related low-energy triplets, long-wavelength phosphorescence emission can be achieved without relying solely on traditional regulation of the intrinsic energy levels of phosphorescent centers. Based on this design philosophy, using (<i>R</i>)-methylbenzylamine and pyromellitic acid as precursors, long-wavelength room-temperature phosphorescent CDs were successfully constructed via a one-step hydrothermal method. Combining femtosecond transient absorption spectroscopy, single-crystal structure analysis, transmission electron microscopy, X-ray photoelectron spectroscopy, and theoretical calculations, it was confirmed that the formation of low-energy CT states induced by matrix effects drives the migration and aggregation of intrinsic triplet excitons toward CT-related low-energy triplets, constituting the key mechanism for long-wavelength phosphorescence generation. The broad applicability of this strategy was further validated using two different representative matrix systems. Therefore, the design strategy for long-wavelength CDs phosphorescence proposed in this study provides a new theoretical framework and design approach for the rational development of long-wavelength and even near-infrared CD-based phosphorescent materials. 2026-09-29T00:00:00Z Text Journal contribution 10.1021/acs.jpclett.6c02632.s001 https://figshare.com/articles/journal_contribution/Triplet_Exciton_Convergence_toward_Charge-Transfer_States_Enables_Long-Wavelength_Room-Temperature_Phosphorescence_from_Carbon_Dots/34021590 CC BY-NC 4.0