Blue–green luminescence and SERS study of carbon‐rich hydrogenated amorphous silicon carbide films with multiphase structure

Abstract

The carbon-rich hydrogenated amorphous silicon carbide (a-Si 1Àx C x :H) films were deposited by plasma enhanced chemical vapor deposition using silane (diluted to 10% in hydrogen) and ethylene as the gas sources. To observe surface enhanced Raman scattering (SERS), some samples were prepared on sputtered Ag films on Si substrates. A variety of techniques including ellipsometer, Fourier transform infrared spectroscopy, Raman scattering, scanning electron microscope, and photoluminescence (PL) spectroscopy were used to characterize the grown films. With enormous enhancement in Raman spectral intensity of carbon related phases and Si-C bonds, SERS is proved to be a powerful method to investigate carbon-rich a-Si 1Àx C x :H films. Multiphase structure of the grown a-Si 1Àx C x :H films is confirmed which possesses hydrogenated sp 3 Si-C network and sp 2 amorphous carbon clusters. Blue-green multiband PL are observed at room temperature. A possible PL mechanism is suggested: the PL originates from exciton-like and geminate recombination of excited electronhole pairs through localized tail states within sp 2 clusters and gap states related to sp 3 Si-C network.

Surface plasmon enhanced blue–green photoluminescence from carbon-rich amorphous silicon carbide films

“…All eight samples exhibited a blue-green RT PL visible to the naked eye. In our previous report, we have confirmed the multiphase structure and PL mechanism of the carbon-rich a-Si 1−x C x :H films used in this work, which consist of hydrogenated sp 3 Si-C network and amorphous carbon clusters [32]. The origin of PL is the radiative recombination of electron-hole pairs within sp 2 bonded carbon clusters in a sp 3 bonded Si-C matrix.…”

“…The flow rates of H2-diluted 10% SiH4 and C2H4 were set at 20 and 10 sccm, respectively. More deposition details can be found in our previous report [32]. A reference sample of a pure a-Si1−xCx:H film was also prepared under the same condition to compare the PL of a-Si1−xCx:H films with Ag interlayer.…”

Uniform Decoration of Reduced Graphene Oxide Sheets with Gold Nanoparticles

“…The increased I D /I G ratio is believed to be caused by the decrease of the mean crystallite size of GO. After removal of the exogenous functional groups in the GO sheets by chemical reduction, and the size of the reestablished GO network is smaller than the original one, which leads to an increase in the I D /I G ratio [24,32,40]. RGO-supported Au NPs can be used as a substrate for surface-enhanced Raman spectroscopy (SERS).…”

Amorphous carbon-based films with surface-plasmon-enhanced full-color photoluminescence

“…The PL of the a-Si 1 − x C x :H films originates from the radiative recombination of electron-hole pairs through the Si-C networks and the radiative recombination of electron-hole pairs within sp 2 bonded carbon clusters in a sp 3 bonded matrix [20,21]. For a-C:H film, PL is only attributed to the radiative recombination within sp 2 carbon clusters [20,22,23].…”

“…The carbon-based films we studied in this work are composed of hydrogenated sp 3 Si-C or C-C network and sp 2 amorphous carbon clusters [20]. The PL of the a-Si 1 − x C x :H films originates from the radiative recombination of electron-hole pairs through the Si-C networks and the radiative recombination of electron-hole pairs within sp 2 bonded carbon clusters in a sp 3 bonded matrix [20,21].…”