Improvement of 1.5 μm photoluminescence from reactive deposition epitaxy (RDE) grown β-FeSi2 balls in Si by high temperature annealing

We found that 900 degrees C annealing was a very effective way to improve the 1.5 mu m photoluminescence (PL) from beta-FeSi2 balls with about 100 nm diameter grown by reactive deposition epitaxy (RDE) and embedded in Si crystals by molecular beam epitaxy (MBE). The full-width at half maximum (FWHM) of the 1.5 mu m PL peak was about 1/4 of chat of the as-grown sample, after annealing at 900 degrees C for 14 h. This was attributed to improvement of the beta-FeSi2 quality. The FWHM of an X-ray diffraction beta-FeSi2 (800) peak decreased from 0.24 degrees to 0.14 degrees by the annealing.