Deep-red light-emitting diodes (DR-LEDs, >660 nm) with high color-purity and narrow-bandwidth emission are promising for full-color displays and solid-state lighting applications. Currently, the DR-LEDs are mainly based on conventional emitters such as organic materials and heavy-metal based quantum dots (QDs) and perovskites. However, the organic materials always suffer from the complicated synthesis, inferior color purity with full-width at half-maximum (FWHM) more than 40 nm, and the QDs and perovskites still suffer from serious problems related to toxicity. Herein, this work reports the synthesis of efficient and high color-purity deep-red carbon dots (CDs) with a record narrow FWHM of 21 nm and a high quantum yield of more than 50% from readily available green plants. Moreover, an exciplex host is further established using a polymer and small molecular blend, which has been shown to be an efficient strategy for producing high color-purity monochrome emission from deep-red CDs via Förster energy transfer (FET). The deep-red CD-LEDs display high color-purity with Commission Internationale de l'Eclairage (CIE) coordinates of (0.692, 0.307). To the best of the knowledge, this is the first report of high color-purity CD-LEDs in the deep-red region, opening the door for the application of CDs in the development of high-resolution light-emitting display technologies.

中文翻译：

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基于绿色植物碳点的超窄带深红电致发光

具有高色彩纯度和窄带宽发射的深红色发光二极管（DR-LED，>660 nm）在全彩显示器和固态照明应用中很有前景。目前，DR-LED 主要基于有机材料和基于重金属的量子点（QD）和钙钛矿等传统发射器。然而，有机材料始终存在合成复杂、色纯度差、半峰全宽（FWHM）超过40 nm的问题，并且量子点和钙钛矿仍然存在严重的毒性问题。在此，这项工作报告了从容易获得的绿色植物中合成了高效、高色纯度的深红色碳点（CD），其半峰宽达到创纪录的 21 nm，量子产率超过 50%。此外，使用聚合物和小分子混合物进一步建立了激基复合物主体，这已被证明是通过福斯特能量转移（FET）从深红色CD产生高颜色纯度单色发射的有效策略。深红色 CD-LED 显示出高色彩纯度，国际照明委员会 (CIE) 坐标为 (0.692, 0.307)。据了解，这是深红色区域高色纯度CD-LED的首次报道，为CD在高分辨率发光显示技术开发中的应用打开了大门。