Photovoltaic Properties of n-type β-FeSi₂/ p-type Si Heterojunctions

Abstract

n-Type β-FeSi2/ p-type Si heterojunction solar cells were fabricated. The energy band diagram was derived from the measured ionization potential of β-FeSi2 and well-known parameters. The value of the built-in potential was estimated to be 1.02 V. Under air mass 1.5 illumination, the cell showed a conversion efficiency of 0.63%. The short-circuit current density was 12.81 mA/cm2, whereas the open-circuit voltage was only 176 mV, which might be attributed to the iron atoms that diffused into the Si depletion region. The iron atoms that diffused cause current leakage and also act as trap centers for the photogenerated carriers.