Probing the growth of β‐FeSi2 nanoparticles for photovoltaic applications: a combined imaging and spectroscopy study using transmission electron microscopy

The microstructure of b-FeSi2 nanoparticles grown using magnetron sputtering on Si has been examined using various electron microscopy techniques. FeSi2 nanoparticles as small as � 4 nm are found embedded in Si after growth using cosputtering of FeSi2 and Si, followed by rapid thermal annealing (RTA). The formation of nanoparticles and its variation in density with Fe content is discussed in terms of phase separation. Our study shows that the size and density of the nanoparticles as well as the extent of Fe diffusion into sputtered Si and substrate can be controlled by controlling the Fe content in the co-sputtered film. Copyright # 2011 John Wiley & Sons, Ltd.