Optical and electrical properties of semiconducting BaSi2 thin films on Si substrates grown by molecular beam epitaxy

Abstract The electrical properties and optical absorption (OA) spectra of undoped BaSi 2 films grown by molecular beam epitaxy were investigated The electron density and mobility of BaSi 2 grown epitaxially on Si(111) were 5 × 10 15 cm − 3 and 820 cm 2 /V·s at room temperature, respectively. The conduction-band discontinuity at the BaSi 2 /Si heterojunction was estimated to be 0.7 eV from the current–voltage characteristics of n -BaSi 2 / n -Si isotype diodes. OA spectra were measured on polycrystalline BaSi 2 films grown on transparent fused silica substrates with predeposited polycrystalline Si layer. The indirect absorption edge was derived to be 1.3 eV, and the optical absorption coefficient reached 10 5 cm − 1 at 1.5 eV.