Nanostructured multilayer metal/por-Si structures based on CoSi₂ film: Optical and electronic properties

To create nanostructured multilayer Co/por-Si structures based on CoSi₂ film with determined size and distribution of the nanocrystals, the interaction between the 6.5-nm Co layer and the por-Si layer surface in vacuum was used. The formation of the self-ordered system based on top layer of CoSi₂ nanocrystals, intermediated layer (130-150 nm) contained 3-11 nm Si nanocrystals, and por-Si layer (1.1; 1.2; 1.4 μm) grown on the single crystal Si was experimentally confirmed by TEM, AFM, scanning tunnelling, IR, and UV - VIS spectroscopies. The formed por-CoSi₂/por-Si structures have novel optical and electronic properties in comparison with por-Si: the IR bands of maximal absorption (648-1275 cm^-1) and maximal reflectance (2000-3200 cm¹¹); the maximal reflectance (up to 80%) at 800-900 nm, the optical bandgap of Si nanocrystals is E_g = 1.2-2.6 eV, and the height of the barrier of CoSi₂/nano-Si structures is 0.7-0.95 eV.