Kristina S. Matyunina

A novel and promising way for creating nanomaterials based on gallium oxide is the ion synthesis of Ga₂O₃ nanocrystals in a SiO₂/Si dielectric matrix. The properties of nanocrystals are determined by the conditions of ion synthesis—the parameters of ion irradiation and post-implantation heat treatment. In this work, the light-emitting properties of Ga₂O₃ nanocrystals were studied depending on the temperature and annealing atmosphere. It was found that annealing at a temperature of 900 °C leads to the appearance of intense luminescence with a maximum at ~480 nm caused by the recombination of donor–acceptor pairs. An increase in luminescence intensity upon annealing in an oxidizing atmosphere is shown. Based on data from photoluminescence excitation spectroscopy and high-resolution transmission electron microscopy, a hypothesis about the possibility of the participation of a quantum-size effect during radiative recombination is proposed. A mechanism for the formation of Ga₂O₃ nanocrystals during ion synthesis is suggested, which makes it possible to describe the change in the luminescent properties of the synthesized samples with varying conditions of post-implantation heat treatment.

The ion-beam synthesis of Ga₂O₃ nanocrystals in dielectric matrices on silicon is a novel and promising way for creating nanomaterials based on gallium oxide. This research studies the regularities of changes, depending on the synthesis regimes used, in the chemical composition of ion-implanted SiO₂/Si and Al₂O₃/Si samples. It has been shown that the formation of Ga-O chemical bonds occurs even in the absence of thermal annealing. We also found the conditions of ion irradiation and annealing at which the content of oxidized gallium in the stochiometric state of Ga₂O₃ exceeds 90%. For this structure, the formation of Ga₂O₃ nanocrystalline inclusions was confirmed by transmission electron microscopy.

A new method for creating nanomaterials based on gallium oxide by ion-beam synthesis of nanocrystals of this compound in a SiO₂/Si dielectric matrix has been proposed. The influence of the order of irradiation with ions of phase-forming elements (gallium and oxygen) on the chemical composition of implanted layers is reported. The separation of gallium profiles in the elemental and oxidized states is shown, even in the absence of post-implantation annealing. As a result of annealing, blue photoluminescence, associated with the recombination of donor–acceptor pairs (DAP) in Ga₂O₃ nanocrystals, appears in the spectrum. The structural characterization by transmission electron microscopy confirms the formation of β-Ga₂O₃ nanocrystals. The obtained results open up the possibility of using nanocrystalline gallium oxide inclusions in traditional CMOS technology.