Structural and optical properties of beta-FeSi2/Si(100) prepared by laser ablation method

beta-FeSi2 is a promising material for the application of various electronic, optoelectronic and energy devices. We present here the semiconducting properties of beta-FeSi2 films on Si(100) substrate prepared by laser ablation method. Samples were grown using poly-crystalline bulk beta-FeSi2 prepared by horizontal gradient freeze method. For the monitoring of growth, in-situ observation of ablation plume was made through fluorescence spectroscopy. Reflection of high energy electron beam diffraction (RHEED) was also made in-situ to see the surface morphology. Characterization of the films by X-ray diffraction presented purely beta(220) orientation. Raman scattering measurements at room temperature also indicated that the grown films are semiconducting beta-FeSi2. Optical absorption spectra at room temperature showed absorption coefficient higher than 10(5) cm(-1) above the band-gap (similar to 1.2 eV). It was revealed that high quality semiconducting beta-FeSi2 films can be fabricated by laser ablation method without post-annealing.