Investigation of electronic structure of Si nanocrystals and their interface with host matrix in P-doped SiO 2:Si and Al 2O 3:Si nanocomposites

Abstract

The system of the nanoinclusions of Si in the SiO 2 and Al 2O 3 matrix (SiO 2:Si, Al 2O 3:Si) attracts great attention due to its ability of the luminescence in visible and near-IR range of spectrum. The influence of the P ion alloying on the electronic structure of nanocomposites was investigated. The P ion doping and post-annealed at T = 1000 °C (2 h) results in the enhancement of the photoluminescence (PL) peak connected with the Si nanocrystals. The electronic structure was investigated by X-ray photoelectron spectroscopy (XPS) and high-resolution electron energy losses spectroscopy (HREELS) methods. Ion surface modification and annealing forms the special nanostructure with Si nanocrystals in SiO 2 and Al 2O 3 matrix having high density of interfaces with special atomic structure and various degree of oxidation of Si atoms on the boundaries. HREELS investigations show that the P ion doping increases the probability of interband transitions in SiO 2:Si and Al 2O 3:Si composites.