Dr. David Beke, Researcher, Institute of Solid State Physics and Optics, Wigner Research Centre for Physics, Hungary

Title: Size Selective Optical and Photocatalytic Properties of Silicon Carbide Nanoparticles

Abstract: Silicon carbide (SiC) is a chemically inert wide band gap semiconductor, and promising new material for bioimaging, targeted drug delivery, nanosensing, optoelectronic and for heterogeneous photocatalysis as well, especially in nano size. Biocompatibility of bulk SiC and SiC nanoparticles (NPs) has been proven by several research teams, and the aqueous solutions of SiC nanocrystals are exceedingly promising candidates to realize bioinert nonperturbative fluorescent nanoparticles for in vivo bioimaging. Thus, size control and the identification of luminescent centers in SiC NPs are of immediate interest. On the other hand, SiC NPs also has intermittently been investigated as a photocatalytic material candidate, a property that might alter the applicability of such NPs in life sciences.

Such a vast variety of promising applications is seeking the needs of the complex understanding of SiC nanosystems. We synthesized SiC-NPs in different sizes close to the exciton Bohr radius using a recently developed method called no-photon exciton generation chemistry (NPEGEC) to study how size affects the optical and photocatalytic activity exactly when energy levels transform from continuous to discrete states, and we found remarkable changes in the physical and chemical behaviors.