Electron localization in self-assembled Si/Ge(111) quantum dots

Abstract

Electron localization in the Si/Ge heterosystem with Si quantum dots (QDs) was studied by transport and electron spin resonance (ESR) measurements. For Si QD structures grown on Ge(111) substrates, the ESR signal with g-factor $g=2.0022\pm0.0001$ and ESR line width $\Delta H\approx1.2$ Oe was observed and attributed to the electrons localized in QDs. The g-factor value was explained by taking into account the energy band modification due to strain effects and quantum confinement. A strong Ge-Si intermixing in QD structures grown on Ge(001) is assumed to be main reason of unobserved ESR signal from QDs. The transport behavior confirms the efficient electron localization in Si QDs.