Germanium quantum dots embedded in a SiO2 matrix fabricated by selective oxidation of SiGe-on-insulator structure were examined by high-resolution transmission electron microscopy, cathodoluminescence spectroscopy, and spectroscopic ellipsometry. The dot size and crystallite morphology were strongly dependent on thermal oxidation conditions. Visible photoemissions from Ge dots were observed at room temperature and they exhibited pronounced blueshifts of peak energies with increasing oxidation time, which can be correlated to the change in dot size, shape, or crystalline structure transition. The extracted refractive index of Ge dots examined by spectroscopic ellipsometry is lower than that of bulk Ge, which is also correlated to the nanocrystal size effects.
|Number of pages||5|
|Journal||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|Issue number||11 A|
|State||Published - 1 Nov 2004|
- Dielectric function
- Quantum dots