Carbon-assisted growth and high visible-light optical reflectivity of amorphous silicon oxynitride nanowires

Abstract

Large amounts of amorphous silicon oxynitride nanowires have been synthesized on silicon wafer through carbon-assisted vapor-solid growth avoiding the contamination from metallic catalysts. These nanowires have the length of up to 100 μm, with a diameter ranging from 50 to 150 nm. Around 3-nm-sized nanostructures are observed to be homogeneously distributed within a nanowire cross-section matrix. The unique configuration might determine the growth of ternary amorphous structure and its special splitting behavior. Optical properties of the nanowires have also been investigated. The obtained nanowires were attractive for their exceptional whiteness, perceived brightness, and optical brilliance. These nanowires display greatly enhanced reflection over the whole visible wavelength, with more than 80% of light reflected on most of the wavelength ranging from 400 to 700 nm and the lowest reflectivity exceeding 70%, exhibiting performance superior to that of the reported white beetle. Intense visible photoluminescence is also observed over a broad spectrum ranging from 320 to 500 nm with two shoulders centered at around 444 and 468 nm, respectively.

Chemical Insight into the Origin of Red and Blue Photoluminescence Arising from Freestanding Silicon Nanocrystals

“…Blue PL has been reported for SiO x N y materials, 48–50 however the exact mechanism remains unknown. Nekrashevich et al .…”

“…Our observations are consistent with nitrogen and oxygen being necessary to induce blue emission from all of the Si NCs presented here. Blue PL has been reported for SiO x N y materials; − however, the exact mechanism remains unknown. Nekrashevich et al have calculated the electronic structure of silicon oxynitride and proposed a possible charge transfer from silicon to nitrogen or oxygen centers as its origin .…”

Glutathione-Functionalized Organosilicon Oxide Nanoparticles for Bioimaging and Forensics

“…In fact, Dasog et al also attributed the presence of nitrogen and oxygen as necessary to induce the blue emission of Si nanocrystals. Moreover, blue PL has been reported for SiO x N y materials. , Nonetheless, the probable origin of the blue emission of Si-based nanomaterials is still under debate and various theories can be found in the literature. For instance, Uchino and co-workers , ascribed the blue emission to the formation of a defect pair consisting of a dioxasilirane (Si­(O 2 )) and a silylene (Si:) as a result of a dehydration reaction between two adjacent geminal silanol groups.…”