Linear and nonlinear optical response of g-C3N4-based quantum dots* *Project supported by the National Key R&D Program of China (Grant No. 2017YFA0303600), the National Natural Science Foundation of China (Grant No. 11974253), and Science Speciality Program of Sichuan University (Grant No. 2020SCUNL210).

Abstract

Graphite carbon nitride (g-C3N4) attracts wide-ranging research interest due to its extraordinary physicochemical properties and promising applications ranging from heterogeneous catalysis to fuel cells. In this work, we design different g-C3N4-based quantum dots (gCNQDs), carry out a systematic study of optical properties, and elucidate the shape selectivity, composite nanostructure, and outfield effect. In particular, composites of gCNQDs and metal nanochains present excellent optical response, making it applicable to bioimaging, nano-plasma devices, and metalloenzyme in infrared light related fields. Besides, QDs which original bridging nitrogen atoms are replaced by amino (–NH2), hydroxyl (–OH), and methyl (–CH3) functional groups respectively, have excellent spectral selectivity in the deep ultraviolet region. More interestingly, in the study of the laser interaction with materials, the gCNQDs exhibit extremely high stability and light corrosion resistance. Phase transition from insulation to metal is observed under the critical condition of about 5 eV intensity or 337 nm wavelength. All provided theoretical support for designs and applications in g-C3N4 quantum devices.