Formation of β-FeSi2 nanodots by SiH4 exposure to Fe nanodots

We have demonstrated the formation of beta-FeSi2 nanodots (NDs) with an areal density as high as 10(11) cm(-2) on SiO2 by exposing Fe NDs to SiH4 at 400 degrees C and characterized their RT light-emission properties. After SiH4 exposure, even at 1.0 Pa for 60 s, stable photoluminescence (PL) signals, being characteristic of the semiconducting phase of beta-FeSi2, were observed in the energy region from 0.7 to 0.85 eV. With an increase in the amount of SiH4 exposure from 60 to 600 Pa center dot sec, PL intensity increased by a factor of similar to 13. Note that, with a further increase in the amount of SiH4 over 600 Pa center dot sec, the PL intensity is weakened slightly. The observed decrease in the PL intensity is attributable to the selective growth of Si onto the NDs after the formation of the beta-FeSi2 phase. (c) 2024 The Japan Society of Applied Physics