Formation of polycrystalline BaSi2 films by radio-frequency magnetron sputtering for thin-film solar cell applications

Polycrystalline BaSi2 films were prepared by means of radio-frequency magnetron sputtering using a BaSi2 target and by post-annealing at 500 °C and above in ultrahigh vacuum. Striped Al electrodes spaced at 1.5 mm were evaporated on the surface. Photocurrents were clearly observed for photon energies greater than approximately 1.25 eV under bias voltages applied between the electrodes. The photoresponsivity increased with bias voltage Vbias and reached approximately 5 mA/W at 1.5 eV when Vbias = 2.0 V.

► BaSi2 films were formed by RF magnetron sputtering.
► The grown film showed n-type conductivity.
► The photoresponse spectra are almost the same as those of epitaxial films.