Photoresponse properties of Al/n-β-FeSi2 Schottky diodes using β-FeSi2 single crystals

We have clearly observed photoresponse properties in an Al/n-beta-FeSi2 structure using beta-FeSi2 single crystals grown by chemical vapor transport. A photocurrent is observed for photons with energies greater than 0.68 eV. It increases sharply with increasing photon energy and attains a maximum at approximately 0.95 eV (1.31 mu m). The photocurrent originated from the photoexcited electrons in the Al and the band-to-band photoexcited carriers in the beta-FeSi2 located under the Al contact. The photoresponsivity increased upon high-temperature annealing, reaching 58 mA/W at 0.95 eV after annealing at 800 degrees C for 8 h. (C) 2007 American Institute of Physics.