Figure 5
(a) Normalized intensity of Γ and Δ2 valley transition depending on the temperature for thermally annealed samples with a different region. A significant activation energy change could be found from the interface region of thermally annealed sample. (b) Comparison of Raman spectra from sample 2-1 and 2-2 under 785 nm laser excitation. (c) Room temperature PL spectra for the thermally annealed samples with different etched depth. (d–f) Illustration of conduction band changes under the influence of strain (d), Si intermixing (e), and in the presence of defect related levels (f). Note that Δ band splits into two bands Δ2 and Δ4 when tensile strained, and the lower energy band becomes Δ2.
