Electron confinement to heteroepitaxial Ge/Si(100) quantum dots encapsulated in a Si matrix was investigated using capacitance-voltage measurements. Optimized growth conditions produced dot ensembles comprised of either huts and pyramids or dome clusters allowing investigation of electron confinement to these distinct dot morphologies. At room temperature, 20-40 nm diameter hut and pyramid clusters confine ∼0.7 electrons, while 60-80 nm diameter dome clusters confine ∼6 electrons. The greater capacity of dome clusters may be attributed to the four distinct conduction band minima that are deeper than the single minimum found for pyramid clusters using a simple band structure model.
ASJC Scopus subject areas
- Physics and Astronomy(all)