Microcrystalline silicon was deposited by hot-wire chemical vapor deposition (HWCVD) using a graphite filament with and without a thin 50 nm microcrystalline silicon seed layer. Increasing silane concentration diluted in H2 led to a decrease in crystalline fraction as well in a decrease in dark conductivity and photo-conductivity. In addition, films deposited with a seed layer were found to have higher dark conductivity and photo-conductivity than those without a seed layer but deposited at slower growth rates. However, Raman spectroscopy showed that use of a seed layer resulted in only a small increase in crystalline fraction at the surface of the films which had thicknesses between 250-400nm. TEM measurements confirmed the crystalline nature of deposited films showing average grain sizes of 25 nm.

P-type hydrogenated microcrystalline silicon (µc-Si:H) thin films (~ 100 nm) were deposited using plasma enhanced chemical vapor deposition (PECVD) at a substrate temperature of 150 °C. RF power density and pressure were varied among films. These films reach a dark conductivity (σ d ) of 10 -1 S/cm, activation energy (E a ) of 10 -2 eV and crystalline volume fraction (X c ) of > 50 %. The structure of these films is composed of nano-sized crystallites embedded in an amorphous matrix, resulting in wide optical bandgap energies (E opt ). Using the Scherrer's formula, grain sizes were estimated to be < 20 nm.

Intrinsic hydrogenated microcrystalline silicon (mc-Si:H) films were prepared by hot-wire chemical vapor deposition (HWCVD) using a graphite filament at a substrate temperature of 210 °C.Films were characterized by Raman Spectroscopy, FTIR and electrical conductivity measurements with varying silane concentrations on glass substrates. Solar cells were fabricated in a glass/SnO2/pin/Al structure and device efficiency was measured to be 2.8%.