Fabrication and characterization of novel Fe(Os)Si2 semiconductor

Ternary Fe(Os)Si2 alloys, a novel semiconducting opto-electronic material with a tuneable direct band gap property, was designed by energy-band engineering. The electronic structures of FeSi2,OsSi2 and (FeOs)Si2 were theoretically calculated using the density functional theory (DFT) method. The thin films were fabricated by magnetic co-sputtering deposition, so as to substitute the Fe sublattice sites by Os. X-ray diffraction, energy dispersion X-ray spectrometry and optical absorption spectroscopy were used to characterize the structural properties of the thin films. Experimental results showed that all the Fe1-xOsxSi2 films have a direct band gap property. The strongest optical absorption was obtained when x is equal to 0.5, which is consistent with the theoretical prediction.