Phase evolution and room-temperature photoluminescence in amorphous SiC alloy

Abstract

Articles you may be interested inPhotoluminescence properties and crystallization of silicon quantum dots in hydrogenated amorphous Si-rich silicon carbide films Room temperature visible photoluminescence of silicon nanocrystallites embedded in amorphous silicon carbide matrix Structural and optical investigation of plasma deposited silicon carbon alloys: Insights on Si-C bond configuration using spectroscopic ellipsometry Amorphous SiC thin films with varying phases and compositions have been synthesized using a low frequency inductively coupled high density plasma source in a hydrogen diluted methane (CH 4 ) and silane (SiH 4 ) mixture. The optical and electrical properties along with the microstructures of the thin films are systematically investigated. The feedstock gas ratio of CH 4 /SiH 4 leads to the fluctuations of the optical bandgap, the carbon content, and the transition of Si-Si bonding structure from crystalline to intermediate phase and finally to amorphous phase. Room temperature photoluminescence (PL) with nearly fixed emission energy has been observed in the thin films. The underlying PL mechanism is explained in the framework of quantum confinement-luminescence center model. The photoexcitation process occurs in the nc-Si quantum dots embedded in the host SiC matrix, whereas the photoemission process occurs in the luminescence centers in the surrounding SiC or at SiC-Si interfaces. The PL evolution with the chemical composition in the films is analyzed in terms of the density of the Si quantum dots and the Si-C bond. V C 2012 American Institute of Physics. [http://dx.

Wide visible and unique NIR fluorescence from SiC nanocrystals embedded in carbon rich SiC matrix derived from liquid polycarbosilane

“…Hence one can conclude that the emission is not originating from the direct transition of 3C-SiC nanocrystals. Zhou et al 26 reported that this kind of emission is explained by surface state model which states that photoexcitation originates from nanocrystals or quantum dots and photoemission occurs in a special surface state. 27 Various surface species related to hydrogen and oxygen has already been reported.…”