Evolution of the surface structure the proton-irradiated tungsten during isochronal annealing in the temperature range 600-1000 °C

This paper presents the research results the surface structure evolution of high-purity tungsten after irradiation with 350 keV protons and subsequent annealing in the temperature range 600 – 1000 °C. Irradiation to a fluence of 5×1017 cm‒2 leads to blisters formation on the irradiated surface. Successive two-hour annealing results in the evolution of the distribution of blisters - the total number of blisters decreases while the fraction of larger blisters increases. At an annealing temperature of 1000C, the blisters dissolve. Do not observed the blisters disclosure and surface flaking both after proton irradiation and subsequent annealing in temperature range 600 – 1000 °C.

Numerical study of silicon vacancy color centers in silicon carbide by helium ion implantation and subsequent annealing

Molecular dynamics (MD) simulation is adopted to discover the underlying mechanism of silicon vacancy color center and damage evolution during helium ions implanted four-hexagonal silicon carbide (4H-SiC) and subsequent annealing. The atomic-scale mechanism of silicon vacancy color centers in the process of He ion implantation into 4H-SiC can be described more accurately by incorporating electron stopping power for He ion implantation. We present a new method for calculating the silicon vacancy color center numerically, which considers the structure around the color center and makes the statistical results more accurate than the Wigner-Seitz defect analysis method. At the same time, photoluminescence (PL) spectroscopy of silicon vacancy color center under different helium ion doses is also characterized for validating the numerical analysis. The MD simulation of the optimal annealing temperature of silicon vacancy color center is predicted by the proposed new method.

Non-equilibrium methods for synthesis and modification of gallium oxide

Synthesis and modification of gallium oxide as a wide-bandgap semiconductor is a topical task in the fields of power electronics, UV detectors, gas sensors, telecommunication. In the present work, the Ga2O3 films deposited on sapphire substrates by magnetron sputtering have been studied. The influence of deposition parameters and subsequent annealing on the structure and optical properties of the synthesized films is analyzed. Ion doping of magnetron-deposited films with silicon is carried out by the ion implantation method. It is shown by the Raman scattering and optical transmission spectroscopy that ion irradiation leads to the disordering of the crystal structure, but subsequent annealing results in a partial recovery of the structure. Hall-effect measurements for irradiated and then annealed films do not reveal the formation of a conducting layer. Apparently, this is due to the fact that the main contribution to the resistance is made by grain boundaries in the magnetron-deposited films.