Ultraviolet Photoluminescence and Electrochemiluminescence From Nanoscale 6H Silicon Carbide Structures
Andrea Rossi, Thomas E. Murphy, Vytas Reipa
Porous silicon carbide films and silicon-carbide nanoparticles have been fabricated using electrochemical etching of a monocrystalline 6H wafer. For the first time we show stable above-bandgap photoluminescence from 6H-SiC nanocrystals, dispersed in water, hydrofluoric acid and toluene. The above-bandgap emission is supported by the particle size measurements together with an estimate of the bandgap expansion caused by quantum confinement. The ultraviolet photoluminescence observed in the SiC colloidal solution is also present in nanoporous SiC under photo excitation. We show that the broadband light emission in nanoporous 6H SiC can be also produced by electrochemiluminescence. The bright emission is centered at 480 nm and could be observed visually.