Temperature dependence of electroluminescence from Si-based light emitting diodes with β-FeSi2 particles active region

Electroluminescence (EL) properties of Si-based light emitting diodes with β-FeSi2 particles active region grown by reactive deposition epitaxy are investigated. EL intensity of β-FeSi2 particles versus excitation current densities has different behaviors at 8, 77 K and room temperature, respectively. The EL peak energy shifted from 0.81 to 0.83 eV at 77 K with the increase of current density from 1 to 70 A/cm2. Temperature dependence of the peak energy can be well fitted by semi-empirical Varshni's law with the parameters of α=4.34 e-4 eV/K and β=110 K. These results indicate that the EL emission originates from the band-to-band transition with the band gap energy of 0.824 eV at 0 K.