Photoconductivity inn-type β-FeSi2single crystals

Abstract
Photoconductivity in β-FeSi2 single crystals was observed in the temperature range of 80–250 K. The energy gap, 0.89 eV at 85 K, and its temperature dependence were determined. The values of the average phonon energy, 55 meV, and the electron-phonon coupling parameter, S=2.75, were evaluated. The observed quenching of photoconductivity is explained in assuming the two-center model. The donor and acceptor activation energy of 70 and 120 meV, respectively, as well as the hole mobility due to lattice scattering were determined.