INVESTIGATION OF THE LUMINESCENCE PROPERTIES OF SI BETA-FESI2/SI HETEROJUNCTION STRUCTURES FABRICATED BY ION-BEAM SYNTHESIS/

Photoluminescence at 1.54 mu m has been observed from discontinuous be ta FeSi2 layers fabricated by ion beam synthesis in silicon wafers. A minimum full width half maximum (FWHM) value of 3 meV, measured at 5 K , was obtained from a sample implanted to a dose of 2 x 10(17) Fe ions cm(-2) at an energy of 200 keV, after an 18 h anneal at 920 degrees C . When the incident energy was increased the FWHM value also increased reflecting the increased residual damage in the sample after annealin g. Room-temperature optical absorption measurements indicate a direct band gap of about 0.86-0.88 eV.