Quantum confinement observed in Ge nanodots on an oxidized Si surface

Abstract

Quantum-confinement effect in the valence band of germanium nanodots is clearly measured by means of photoemission spectroscopy. The spherical dots of $3--10\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ in diameter were prepared on a $0.3\text{\ensuremath{-}}\mathrm{nm}$-thick $\mathrm{Si}{\mathrm{O}}_{2}$ film on Si(111) substrate. Dot-size dependence of the band edge matched the ones expected from the spherical quantum dot model and calculated from the semiempirical simulation recently reported.