[en] A series of investigations were performed to study the influence of the substrate temperature on the structure and properties of silicon thin films. Substrate temperature was varied in the wide range of 35-200 deg. C. It has been shown that the films grown below 60 deg. C exhibit an unusual structural behavior. A sharp TO phonon peak at 520 cm^-1 was detected in Raman spectra, which is associated with the crystalline structure. In contrast to these results, the same samples do not show any crystallite-related peak by X-ray diffraction and their optoelectronic properties (dark conductivity, activation energy and subgap absorption spectra) show amorphous features. A similar discrepancy was observed for a hydrogen dilution ratio (r_H=([SiH₄]+[H₂])/[SiH₄]) series of samples deposited at 60 deg. C. Hydrogen dilution ratio was varied from 25 to 170. It seems that at low substrate temperature a parameter window exists where the silicon thin films can be grown with the properties combining both crystalline and amorphous behavior

[en] Silicon nanowires and nanoneedles show promise for many device applications in nanoelectronics and nanophotonics, but the remaining challenge is to grow them at low temperatures on low-cost materials. Here we present plasma-enhanced chemical vapor deposition of crystalline/amorphous Si nanoneedles on glass at temperatures as low as 250 deg. C. High resolution electron microscopy and micro-Raman spectroscopy have been used to study the crystal structure and the growth mechanism of individual Si nanoneedles. The H₂ dilution of the SiH₄ plasma working gas has caused the formation of extremely sharp nanoneedle tips that in some cases do not contain a catalytic particle at the end.

[en] A boundary between amorphous and microcrystalline growth of silicon thin films was explored for the study of grain growth by changing parameters of plasma enhanced deposition (substrate temperature, silane dilution or deposition duration and thus the film thickness). Resulting series of a-Si:H/μc-Si:H samples were characterized by values of dark conductivity and corresponding activation energy and prefactor, diffusion length, hydrogen content and morphology. The abrupt change of conductivity at the boundary is accompanied by a peak in surface roughness and diffusion length, which were connected to the formation of a percolating network of microcrystalline large grains. Results are discussed using the idea of barriers for electronic transport forming at the large grain boundaries. Comparison of transport properties with the hydrogen content pointed out the fundamental role of hydrogen present at the grain boundaries

[en] Here we present two ways of preparing lateral (in plane) silicon nanowires with the help of gold nanoislands catalysed plasma enhanced chemical vapour deposition. The role of the applied potential and eventual consecutive hydrogen plasma treatment is tested together with the thickness of the thin Au layer used for self-organised preparation of Au nanoislands. (author)