Atomic-scale model ofc−Si/a-Si:H interfaces

We present the first atomic-scale numerical study of the c-Si/a-Si:H interface structure, based on combined tight-binding molecular dynamics simulations and ab initio electronic structure calculations. We generate models with different realistic H concentrations, up to 11%, following two distinct procedures. We discuss the effects on the topological and electronic properties due to the H content and to the different generation protocols. We obtain model junctions with a realistic percentage of topological defects and showing either a trend to amorphization of the c-Si region or a trend to recrystallization of the a-Si:H region. These are indications of the variety and complexity of the processes present in the real samples, and also suggest that our numerical samples are representative of some realistic cases.