Study of Defect Structure of Silicon Doped with Dysprosium Using X-Ray Phase Analysis and Raman Spectroscopy

In this paper, the effect of doping silicon with dysprosium (Dy) on its structural and optical characteristics is investigated. Silicon n-Si was doped with dysprosium by thermal diffusion at 1473 K for 50 h. Raman spectroscopy and X-ray diffraction analysis were used for the analysis. The Raman spectroscopy results showed a main peak at 523.93 cm⁻¹, corresponding to n-Si optical phonons, with an increase in the intensity and full width at half maximum (FWHM) in n-Si<Dy> samples, indicating an improvement in the crystallinity of the structure. A decrease in the intensity of the peaks at 127.16 cm⁻¹ and 196.24 cm⁻¹, associated with amorphous structures, confirms a decrease in defects. The detection of a new peak at 307.94 cm⁻¹ indicates successful deposition of dysprosium as nanocrystallites associated with the 2TA phonon mode in the cubic phase of Dy2O3. X-ray diffraction analysis revealed characteristic structural lines indicating the (111) crystalline orientation and the presence of microdistortions in the lattice. Heat treatment and rapid cooling lead to a change in the intensity of structural lines, an increase in the second- and third-order lines, which indicates microstrains and a change in the size of subcrystallites. Doping of silicon with dysprosium improves the crystallinity of the structure, reduces the number of defects and forms polycrystalline layers on the surface consisting of SiO2 and Dy2O3 nanocrystals.