Magnetron Sputtered Hydrogenated Silicon Thin Films: Assessment for Application in Photovoltaics

Abstract

Hydrogenated amorphous and nanocrystalline silicon (a-Si:H, nc-Si:H) thin films have been prepared by radio frequency magnetron sputtering with process parameters used to manipulate optical properties, structure, and growth evolution. In-situ real time spectroscopic ellipsometry is applied to construct growth evolution diagrams by tracking nucleation and coalescence of crystallites from the amorphous phase, as well as surface roughening within the amorphous growth regime, as functions of hydrogen-to-argon gas ratio. Infrared spectroscopic ellipsometry determines Si-H _n vibrational modes, and grazing incidence x-ray diffraction provides crystallite orientation. The suitability of these materials for photovoltaics is assessed.