Cryogenic Studies of PL From Polymer Nanocomposites of 2D layered SiC NCs

While the nature of photoluminescence (PL) relaxation in 2D layered vitrified colloidal silicon-carbide (SiC) nanocrystals (NCs) is still developing, efficient PL from SiC NC polymer nanocomposites has significant potential implications for new biolabeling and solar-collection technologies. In this study, we investigate the specifics of PL relaxation in photopolymerized off-stoichiometric polymer nanocomposites of 2D layered SiC NCs. In detail, tetra-functional thiol, tri-functional allyl, and a series of dodecyl-passivated colloidal 2D layered SiC NCs are used to create a series of thiol-ene polymer/nanocrystal composites. We explore their PL relaxation in the parameter space of emission wavelength, quantum yield, and temperature, concentrating on the observed changes in PL relaxation time upon cooling to cryogenic conditions. The nanocomposites exhibit air-stable blue emission, with our results providing physical insight into the nature of surface and impurity emission from these emerging materials.