Absorption of Si, Ge, and SiGe alloy nanocrystals embedded in SiO2 matrix

摘要: Using the atomistic s p 3 d 5 ∗ tight-binding method, we calculate optical absorption spectra due to phononless transitions in Si, Ge, and SiGe alloy nanocrystals embedded an amorphous dielectric SiO 2 matrix. For matrix, use a virtual crystal approximation assuming cubic crystalline structure, similar β crystobalite, proximity of nanocrystal surface. The is analyzed detail: its dependency on Ge content size role matrix are revealed. Our recent experimental measurements co-sputtered thin films with arrays discussed compared simulations.