Quantum confinement effects in Si/Ge heterostructures with spatially ordered arrays of self-assembled quantum dots

摘要

Magnetotunneling spectroscopy was employed to probe the confinement invertical Si/Ge double-barrier resonant tunneling diodes with regularlydistributed Ge quantum dots. Their current-voltage characteristics reveal astep-like behavior in the vicinity of zero bias, indicating resonant tunnelingof heavy-holes via three-dimensionally confined unoccupied hole states in Gequantum dots. Assuming parabolic confinement we extract the strength of theconfinement potential of quantum dots.