Grain boundaries characterization of semiconducting BaSi2 thin films on a polycrystalline Si substrate

Grain boundaries (GBs) and crystalline quality of semiconducting BaSi₂ films grown on polycrystalline Si (pc-Si) substrates by molecular beam epitaxy were analyzed using Kelvin probe force microscopy and electron back scattered diffraction. It was found that the degree of a-axis-orientation of BaSi₂ was dependent on local crystal orientations of the pc-Si, and thus the surface electrostatic potential varied from place to place. At the GBs of Si, there was not so much difference in potential variations compared to GBs in BaSi₂ formed on single crystalline Si(111). The barrier height was approximately 20-40 meV for holes. The GBs of BaSi₂ around Σ3 GBs of Si don´t work as recombination center for minority carriers.