Correlated Structural and Luminescence Analysis of B‐Doped Si‐Nanocrystals Embedded in Silica

International audienceStructural characteristics and luminescence properties of B-doped silicon nanocrystals (Si-ncs) embedded in a SiO2 matrix elaborated by ion beam synthesis are investigated. The use of atom probe tomography gives a unique opportunity to experimentally evidence the exact location and composition of B atoms in doped Si-ncs. These experiments allow to conclude about a favored B location at the periphery of the Si-ncs depending on their size. In this way, two categories of Si-ncs can be described: 1) largest Si-ncs that are B-doped and where B atoms are located at the Si-ncs/SiO2 interface, and 2) smallest Si-ncs that remain undoped but seem to be surrounded by a B-rich SiO2 shell. These structural characteristics (composition and diameters) are correlated to the photoluminescence properties of these Si-ncs. These measurements show the well-known quenching of Si-ncs luminescence due to high B doping, which allows us to conclude about the environment changes brought by the presence of B in Si-ncs or of B-rich shell around Si-ncs