Abstract
n-type beta-FeSi2/p-type Si heterojunction photodiodes were fabricated by facing-targets direct-current sputtering, and their near-infrared photodetection properties were studied in the temperature range of 50-300 K. At 300K, devices biased at -5 V exhibited a current responsivity of 16.6 mA/W. The measured specific detectivity was remarkably improved from 3.5 x 10(9) to 1.4 x 10(11) cmHz(1/2)/W as the devices were cooled from 300 K down to 50 K. This improvement is mainly attributable to distinguished suppression in heterojunction leakage current at low temperatures. The obtained results indicate that beta-FeSi2/Si heterojunctions offer high potential to be employed as near-infrared photodetectors that are compatible with the current Si technology. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4789391]