Self-Ordered Voids Formation in SiO₂ Matrix by Ge Outdiffusion

Figure 8

UV-Vis reflectance spectra of the as-deposited sample (SiO₂/Ge multilayers, blue curve), annealed sample (substantially SiO₂ with voids, red curve), and pure silica layer of the same thickness (green curve) on Si substrate. The clean Si substrate was also measured for comparison (black curve).