Preparation and characterization studies of nanostructured silicon thin films using rf magnetron sputtering

High quality Silicon thin films are prepared using planar RF magnetron sputtering technique. GIXRD and Raman spectra of the films show broad peaks of Si indicating that they are either amorphous or nanostructured in nature consisting of particles of very small size. The optical band gap energy estimated from the Tauc plot for the films prepared RF powers at 200, 250 and 300 W is found to be 2.87, 3.21 and 2.33 eV respectively. The enhanced band gap energy for the films compared to the bulk silicon supports the presence of quantum confinement in the films due to the presence of nanoparticles. Grain size and root mean square (rms) surface roughness of the deposited films are determined from the AFM analysis and are found to be increases with increase in RF power. The films exhibit strong photoluminescence emission in the visible region.