Carbon dots (CDs) demonstrate great superiority in optoelectronic devices due to their tunable emission and photobleaching resistance properties. Although the fluorescence of CDs in solution has been extensively studied, their solid‐state fluorescence (SSF) mechanism still remains largely unexplored experimentally. Herein, solid‐state fluorescent CDs with unique clusteroluminescence (CL) generated from clusterization‐triggered emission are designed based on condensation between precursors with carboxyl and amino groups. The CDs demonstrate obvious concentration‐dependent fluorescence and quench‐resistant SSF, which is attributed to the activation of amide (n, π*) transition by the clusterization process. This sub‐luminophore is non‐luminescent at long wavelengths in isolated state, while it induces photoluminescence redshift via through‐space interaction in aggregated state. Besides, the SSF of CDs can be tuned from quenched to quenching‐resistant emission through amide formation, and the dominant fluorescent center of CDs solids is switchable from surface to edge state through amide passivation. Based on their long‐wavelength CL feature, high‐purity red light‐emitting diode devices exhibiting 656‐nm warm light are fabricated with the Commission Internationale de l´Eclairage (CIE) coordinates of (0.66, 0.34) and unchanged wavelength under different driving currents. These findings provide novel insights into the SSF mechanism of CDs and a universal strategy to construct fluorescent materials with tailored properties.

The traditional self-supported piezoelectric thin films prepared by filtration methods are limited in practical applications due to their poor tensile properties. The strategy of using flexible polyethylene terephthalate (PET) fabric as the flexible substrate is beneficial to enhancing the flexibility and stretchability of the flexible device, thus extending the applications of pressure sensors. In this work, a novel wearable pressure sensor is prepared, of which uniform and dense ZnO nanoarray-coated PET fabrics are covered by a two-dimensional MXene nanosheet. The ternary structure incorporates the advantages of the three components including the superior piezoelectric properties of ZnO nanorod arrays, the excellent flexibility of the PET substrate, and the outstanding conductivity of MXene, resulting in a novel wearable sensor with excellent pressure-sensitive properties. The PET/ZnO@MXene pressure sensor exhibits excellent sensing performance (S = 53.22 kPa−1), fast response/recovery speeds (150 ms and 100 ms), and superior flexural stability (over 30 cycles at 5% strain). The composite fabric also shows high sensitivity in both motion monitoring and physiological signal detection (e.g., device bending, elbow bending, finger bending, wrist pulse peaks, and sound signal discrimination). These findings provide insight into composite fabric-based pressure-sensitive materials, demonstrating the great significance and promising prospects in the field of flexible pressure sensing.

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