Correlation of structural and electrical transport properties in hydrogenated silicon films

In this work we report on the correlation between the structural properties, i.e. crystalline/amorphous phase ratio and grain size, and the electrical transport properties of hydrogenated silicon thin films. The samples were deposited by means of pulsed laser ablation of a high purity silicon target in presence of hydrogen gas. Infrared spectroscopy measurements showed a monohydride preferential incorporation at the lower hydrogen pressures. The Raman spectroscopy studies of the TO phonon line suggest that crystallinity and hydrogenation of the films, deposited at room temperature, can be properly adjusted as a function of the deposition parameters. The temperature dependence of both the dark and the photo electrical conductivity shows a thermally activated behaviour, which is strictly related to the silicon microstructure and to the hydrogen content and bonding configuration.