Ligand‐Triggered Self‐Assembly of Flexible Carbon Dot Nanoribbons for Optoelectronic Memristor Devices and Neuromorphic Computing

Abstract

Carbon dots (CDs) are widely utilized in sensing, energy storage, and catalysis due to their excellent optical, electrical and semiconducting properties. However, attempts to optimize their optoelectronic performance through high-order manipulation have met with little success to date. In this study, through efficient packing of individual CDs in two-dimensions, the synthesis of flexible CDs ribbons is demonstrated technically. Electron microscopies and molecular dynamics simulations, show the assembly of CDs into ribbons results from the tripartite balance of 𝝅-𝝅 attractions, hydrogen bonding, and halogen bonding forces provided by the superficial ligands. The obtained ribbons are flexible and show excellent stability against UV irradiation and heating. CDs ribbons offer outstanding performance as active layer material in transparent flexible memristors, with the developed devices providing excellent data storage, retention capabilities, and fast optoelectronic responses. A memristor device with a thickness of 8 µm shows good data retention capability even after 10 4 cycles of bending. Furthermore, the device functions effectively as a neuromorphic computing system with integrated storage and computation capabilities, with the response speed of the device being less than 5.5 ns. These properties create an optoelectronic memristor with rapid Chinese character learning capability. This work lays the foundation for wearable artificial intelligence.

High-efficiency NP-carbon dots above 60% with both delayed fluorescence and room-temperature phosphorescence

“…This means that the NP-CDs possess various emissive group structures. 21–23 Moreover, the NP-CD afterglow emission spectra also display excitation-correlated behavior (Fig. S5, ESI†), consistent with the PL emission spectra.…”

Surface Modification Functionalized Carbon Dots

“…SA-CDs with aggregation-induced emission can expand the controlled synthesis strategies of CDs in the field of matterfree solid-state fluorescence and self-assembly. [59][60][61]…”

“…Salicylaldehyde (SA) ligands functionalized on the surfaces of CDs can induce macroscopic self‐assembly in the CDs (Figure 5a) and continuously tunable optical emission from blue to deep red (Figure 5b). SA‐CDs with aggregation‐induced emission can expand the controlled synthesis strategies of CDs in the field of matter‐free solid‐state fluorescence and self‐assembly [59–61] …”

Carbon Dot Based Multicolor Electroluminescent LEDs with Nearly 100% Exciton Utilization Efficiency

“…The C originates mainly from the perylene precursor, and the N originates from the 1,3-diaminopropane precursor, while O is from the solvothermal oxidation/carbonization process (Figure e). The high resolution of C 1s (Figure f), N 1s (Figure S3a), and O 1s (Figure S3b) spectra indicates that carbon dots contain abundant functional groups . Fourier transform infrared spectroscopy (FTIR) was next applied to analyze the functional groups in the CDs.…”

“…The high resolution of C 1s (Figure 1f), N 1s (Figure S3a), and O 1s (Figure S3b) spectra indicates that carbon dots contain abundant functional groups. 30 Fourier transform infrared spectroscopy (FTIR) was next applied to analyze the functional groups in the CDs. The FTIR spectrum of the CDs (Figure 1g) corresponds to XPS, revealing that the CDs possessed a typical sp 2 /sp 3 hybrid model with abundant side chains and surface functional groups.…”