Abstract
n-Type nanocrystalline-FeSi2/p-type Si hetero-junctions were prepared at room temperature by means of a facing target direct-current sputtering method. The current density-voltage (J-V) characteristics of the devices fabricated were investigated in the temperature range of 77-300 K. At a wavelength of 1.31 mu m, the photodiodes exhibited a room-temperature responsivity of 110 mA/cm(2) and a detectivity of 2.7 x 10(8) cm root Hz/W, which was improved to 1.5 x 10(10) cm root Hz/W at 77 K. The results profile an attractive low-cost near-infrared photodiode suitable for large-area optoelectronics.