Photoresponse properties of Al-β-FeSi_2 Schottky diodes using β-FeSi_2 single crystals

摘要

We have clearly observed photoresponse properties in an Al-β-FeSi_2 structure using β-FeSi_2 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 μm). The photocurrent originated from the photoexcited electrons in the Al and the band-to-band photoexcited carriers in the β-FeSi_2 located under the Al contact. The photoresponsivity increased upon high-temperature annealing, reaching 58 mA/W at 0.95 eV after annealing at 800 ℃ for 8 h.