Carbon Dots with Charge Storage Ability Promote the Red Emission of TFB via Carrier Secondary Injection

Dual-emission light-emitting diodes (DEDs) have great promising applications in medical imaging, optical communication, data storage, and three-dimensional display. The precise material design and advanced packaging technology for the construction of DEDs are still key challenges for practical application. We demonstrate a straightforward strategy to construct DEDs that deviates from traditional approaches, utilizing commercially available luminescent material of poly(9,9-dioctylfluorene-co-N-(4-(3-methylpropyl))diphenylamine) (TFB) and carbon dots (CDs). In the DEDs, the mixture of CDs and TFB was used as the luminescent layer, which exhibits dual-wavelength emission located at 436 and 632 nm, respectively. Notably, the CDs, with charge storage ability, can store the interfacial charges, reinject the carriers into TFB, and then facilitate the long-wavelength (632 nm) emission from TFB. This work provides a new way for the design and construction of fresh DEDs through the CD-based interfacial charge transport process.