The electron and crystalline structure features of ion-synthesized nanocomposite of Si nanocrystals in Al2O3 matrix revealed by electron spectroscopy

The luminescence yield depends on structure of Si nanocrystals embedded into Al2O3 matrix, matrix lattice defects, chemistry, and accommodation discordance at the interfaces. The physical ground of this phenomenon is connected with a competition between radiative and nonradiative transitions. The Si-NC were formed in the C-cut sapphire wafers, and electron-gun deposited Al2O3 films on Si substrate by Si+ by ion implantation and post-implantation annealing at 500-1100 degrees C. XPS depth profiling allowed revealing electron and crystalline structure of Si+-implanted sapphire layers, depth distribution of Si nanocrystals, matrix defects, accommodation stresses, and electron transitions. The presence of defects at the Si nanocrystal/ Al2O3 interfaces originated from the accommodation discordance leads to severe degradation of light-emitting properties of Si nanocrystals in sapphire.