Fluorescent Silicon Carbide Nanoparticles

Silicon carbide (SiC) is an indirect wide band gap semiconductor that is utilized in many industrial applications due to its extreme physical properties. SiC nanoparticles (NPs) exhibit a versatile surface chemistry, fluoresce from the ultraviolet to the near-infrared spectral ranges, and their sizes can be tuned from one to hundreds of nanometers. Yet, fluorescent SiC NPs have received far less attention by the scientific community. This review summarizes the state-of-the-art in fluorescent SiC NPs. Nanoparticle fabrication methods, characterization techniques, nanoparticle surface chemistry, and SiC NPs fluorescence properties are assessed in detail. Atomic defects and impurities in the SiC crystal lattice (so-called color centers), surface-induced fluorescence, quantum confinement, and band-edge fluorescence are identified as the main sources of fluorescence in SiC NPs. While many color centers are reported in bulk SiC, only few are identified in SiC NPs and interface-related defects remain poorly understood, creating enormous potential for scientific discovery. Finally, an overview of demonstrated and emerging potential applications of SiC NPs in the areas of bioimaging and quantum sensing is provided.