pH-controlled construction of 2D and 3D micro-nano hybrid carbon architectures with fluorescence/phosphorescence dual-mode emission for white-emitting diodes

• Published in: Carbon (New York) Vol. 214; p. 118355
• Main Authors: Qu, Jian, Zhang, Xin, Gu, Rong, Gu, Zimeng, Lu, Xiulian, Zhang, Zhengyu, Yang, Hongyu, Jing, Su
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2023
• Subjects: 3D carbon architectures; Carbon dots; Hybrid fluorescence/phosphorescence; White light-emitting diodes; Carbon dots; 3D carbon architectures; Hybrid fluorescence/phosphorescence; White light-emitting diodes
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2023.118355

Developing nanocarbon-based white-emitting diodes (WLEDs) with high energy conversion efficiency is still extremely challenging due to the issue of Kasha's rule and serious self-aggregation caused luminescent quenching of nanocarbon in a solid-state. Herein, the synergistic strategy of framework and intercalator between nanosheets and carbon dots (CDs) was adopted. Three novel 2D nanosheets, 3D nanoflowers and 3D parasa consocia-like micro-nano carbon architectures decorated with dispersive CDs were successfully fabricated through one-step hydrothermal reaction at different pH medium. The pH-regulated mechanisms of morphology and structure, via degree modulation of condensation and carbonization, were further proposed. All samples exhibited bright white emission, derived from fluorescence/phosphorescence dual-mode emission. The hybrid emission made sufficient utilization of single and triplet excitons with the quantum yield of 16%–30%. The superior white light with CIE coordinates of (0.331,0.334) was recorded for neutral sample (p-CNDs-N), ascribed to the multiple energy level transitions from polydisperse luminescence centers. The luminous efficiency was remarkably improved in HCl (p-CNDs-H) and NaOH treated samples (p-CNDs-OH), resulting from inner carbonization, external cross-linked network and the passivation of surface defect sites. This is the first example for pH-controlled fabrication of multi-dimension hybrid nanocarbon structures and pH-controlled fluorescence/phosphorescence dual-mode emission for highly efficient carbon-based WLEDs. [Display omitted]