Influence of the layer thickness in plasmonic gold nanoparticles produced by thermal evaporation.

Metallic nanoparticles (NPs) have received recently considerable interest of photonic and photovoltaic communities. In this work, we report the optoelectronic properties of gold NPs (Au-NPs) obtained by depositing very thin gold layers on glass substrates through thermal evaporation electron-beam assisted process. The effect of mass thickness of the layer was evaluated. The polycrystalline Au-NPs, with grain sizes of 14 and 19 nm tend to be elongated in one direction as the mass thickness increase. A 2 nm layer deposited at 250°C led to the formation of Au-NPs with 10-20 nm average size, obtained by SEM images, while for a 5 nm layer the wide size elongates from 25 to 150 nm with a mean at 75 nm. In the near infrared region was observed an absorption enhancement of amorphous silicon films deposited onto the Au-NPs layers with a corresponding increase in the PL peak for the same wavelength region.

Role of trimethylboron to silane ratio on the properties of p-type nanocrystalline silicon thin film deposited by radio frequency plasma enhanced chemical vapour deposition.

Trimethylboron (TMB) has been receiving attention as a valid alternative to diborane and methane mixtures for the deposition of p-type silicon films for applications in optoelectronic devices such as solar cells. In this paper we report on p-type hydrogenated nanocrystalline silicon carbide (nc-Si:C:H) films produced by standard 13.56 MHz plasma enhanced chemical vapour deposition technique, using TMB as gas source, under high hydrogen dilution (98%) and using high deposition pressures (3 Torr). The films obtained were characterized by spectroscopic ellipsometry (SE), Raman spectroscopy (RS), and electrical measurements to determine their optical, structural and electrical properties. We achieved conductivities as high as 8.3 (omega cm)(-1), one of the highest values of conductivity published to date using TMB with standard rf-PECVD. Spectroscopic ellipsometry modeling revealed that the films growth mechanism proceeds through a sub-surface layer mechanism that leads to the formation of nanocrystalline silicon.