Nanocarbon with a Wide Bandgap Derived From Self‐Assembly of Polynaphthalene Derivatives

Carbon semiconductors, as an emerging class of materials, have demonstrated significant potential in various applications. A key factor governing their performance is the precise control of the bandgap. Theoretical predictions indicate that introducing defects into carbon semiconductor crystal structures is an effective strategy for widening their bandgap. Based on this, this study utilized polynaphthalene derivatives as precursors and prepared well‐dispersed nanocarbon materials by carbonizing them in a mixed molten salt system at 650°C. This material is self‐assembled from a series of polycyclic aromatic hydrocarbon molecules with different molecular weights and structures, yielding a crystal structure rich in defects. The optical bandgap of the resulting materials was calculated to be 5.45 eV based on their UV absorption spectrum. Furthermore, Hall effect measurements at 298 K confirmed its semiconductor characteristics, exhibiting a resistivity of 469 Ω/cm, the Hall coefficient of 3989 cm 3 /C, the carrier density of 1.56 × 10 15 cm −3 , and the Hall mobility of 8.5 cm 2 /V s. This material is expected to be applied as a wide bandgap semiconductor in energy conservation, optoelectronics, and other fields.