Effects of annealing temperature on shape transformation and optical properties of germanium quantum dots |
Two-dimensional AFM images of Ge QDs on Si substrates, pre-annealed (a) annealed at 300 °C (b), 450 °C (c), and 650 °C (d). Insets show the sizes and shapes of selected dots. Transition stage from pyramidal for pre-annealed (e) to dome-like structure post-annealed at 650 °C (h) is shown at high magnification 3D images of the selected QDs. |