Introduction to Carbon Quantum Dots

Carbon quantum dots (CQDs) are a new class of emerging fluorescent materials which have gained attention in various fields of science and engineering. They are particles with size less than 10 nm and notable physicochemical properties. The performance of CQDs chiefly depends on the source of carbon, the passivator used, and the synthesis parameters followed. CQDs possess exceptional properties such as up-converted luminescence, biocompatibility, low toxicity, photostability, charge transport, superconductivity, etc. These unique features of CQDs make it an ideal candidate in various applications including sensors, catalysis, energy storage, solar cells, optoelectronics, bioimaging, biomedicine, etc. Also, the sp 2 -conjugated structure of CQDs surrounded with hydroxyl and carboxyl groups facilitates easy functionalization with other organic molecules. This chapter provides a systematic view on key advancements in the development of CQDs encompassing preparation techniques, structural properties, and strategic applications in various fields. It is believed that this piece of work could bring valuable insights on investigating CQDs as the potential material in practical applications. Moreover, this could also be beneficial for interdisciplinary research community working in the field of nanotechnology.