Abstract
n-type beta-FeSi2/p-type Si heterojunctions were fabricated from beta-FeSi2 films epitaxially grown on Si(111) by facing-target direct-current sputtering. Sharp film-substrate interfaces were confirmed by scanning electron microscopy. The current-voltage and photoresponse characteristics were measured at room temperature. They exhibited good rectifying properties and a change of approximately one order of magnitude in the current at a bias voltage of -1 V under illumination by a 6 mW, 1.31 mu m laser. The estimated detectivity was 1.5x10(9) cm root Hz W at 1.31 mu m. The results suggest that the beta-FeSi2/Si heterojunctions can be used as near-infrared photodetectors that are compatible with silicon integrated circuits.