We have investigated an optimal annealing process in order to enhance 1.55 mu m light emission from semiconducting beta-FeSi2 and found that two steps annealing at 600 degrees C and 800 degrees C is effective to its enhancement. Rutherford backscattering spectroscopy and SEM observations revealed that pronounced surface segregation of Fe atoms during annealing at 600 degrees C caused surface precipitate of beta-FeSi2. The enhancement of light emission is attributed spatial isolation of the surface beta-FeSi2 (light emitting layer) from damaged and defective layers with nonradiative recombination centers. (c) 2007 Elsevier B.V. All rights reserved.