Abstract
n-Type β-FeSi2/intrinsic Si/p-type Si heterojunction photodiodes were prepared by facing-targets direct-current sputtering, and their near-infrared light detection performances were evaluated in the temperature range of 50 - 300 K. The rectification current ratio at bias voltages of {plus minus}1 V and the ratio of the photocurrent to the dark leakage current were remarkably enhanced with a decrease in the temperature. The detectivity at zero bias was estimated to be 3.8×109 cmHz1/2 /W at 300 K, and it was enhanced to be 8.9×1011 cmHz1/2/W at 50 K. It was demonstrated that β-FeSi2 is a potential material applicable to near-infrared photodetectors that are compatible with Si.