The effects of bias polarity on diamond deposition by hot-filament chemical vapor deposition

Electric voltages with both polarities were applied to silicon substrates in a hot-filament chemical vapour deposition device to study the biasing effects on deposition of diamond and carbon nanocones. It has been found that positive biasing greatly enhanced diamond nucleation density and improved diamond film quality. On the other hand, negative biasing promotes deposition of dense, well-aligned carbon nanocones. The orientation of the carbon nanocones appears to align with the direction of the electric field lines near the substrate surface.PACS Nos.: 81.15.Gh, 81.05.Uw, 81.07.–b

Photoluminescence and Raman Scattering Correlated Study of Boron-Doped Silicon Nanowires

Boron-doped (B-doped) silicon nanowires (SiNWS) have been prepared and characterized by Raman scattering and photoluminescence (PL). B-doped SiNWS were grown by plasma enhanced chemical vapor deposition (PECVD), using diborane (B2H6) as the dopant gas. Raman spectra show a band at 480cm-1,which is attributed to amorphous silicon. Photoluminescence at room temperature exhibits three distinct emission peaks at 1.34ev,1.42ev,1.47ev. Possible reason for these is suggested. PACS: 36.40._c; 81.15.Gh; 81.20._n