Preparation and optical properties of sulfur-doped silicon oxide microbelts and microrods

Abstract

Amorphous S-doped and non-doped silicon oxide (SiO 2 ) one-dimensional structures with various morphologies are synthesized on Si substrates by vapor deposition with Ag 2 S as the precursor in a horizontal tube furnace. Curved microwires, grass-like microwires, S-doped microbelts, and straight S-doped microrods are obtained at the downstream of the furnace with different deposition temperatures in sequence. The microwires and microbelts are formed by the direct vapor-solid mechanism. The morphologies of microwires are largely determined by the inherent isotropy of their amorphous structure and the competitive growth in vapor phase. The microbelts are formed by the lateral growth of small microwires and the doped S played a critical role in their formation. However, the Ag–Si–S–O nanoparticles located at the growth ends suggests that the formation of S-doped SiO 2 microrods should be controlled by the vapor-liquid-solid mechanism. Both curved and grass-like microwires have similar photoluminescence behavior with strong blue/green/yellow bands and weak violent/red bands. However, S-doped microbelts exhibit strong violet/blue bands and relative strong a red band, and S-doped microrods exhibit low violet/blue bands and a strong red band. The obvious shifts in the intensities and wavelengths of the violet/blue/yellow bands are attributed to the morphology/size effects of microwires and microbelts, while the improved red-light emission is assigned to the doped S in microbelts and microrods. • S-doped SiO 2 nanobelts and nanorods are synthesized by vapor deposition. • S-doped SiO 2 nanobelts and nanorods are twist-free and straight. • Doped S determines the formation and morphology of the nanobelts. • Doped S can tune the optical properties of the nanobelts and nanorods.