Abstract:
An $n$-type GaN layer doped with Sn was grown by hydride vapor-phase epitaxy (HVPE). Tin doping was carried out by a chemical reaction with the formation of SnCl$_2$ and its subsequent decomposition in the presence of NH$_3$. It has been shown that doping with tin leads to the disappearance of cracks and a decrease in the roughness of GaN. The optical properties of tin-doped GaN have been investigated. It is shown that in the Raman spectrum of GaN : Sn a thick zone of lines appears in the region from 620 to 740 cm$^{-1}$, associated with fluctuations in Sn–N bonds. The conduction electrons produced by doping GaN with tin absorb light in the region of 2.2–3.3 eV. Using the density functional theory, it is shown that Sn atoms strongly interact with each other in a GaN crystal in an anisotropic manner, determining the local symmetry group of the doped crystal.
Keywords:gallium nitride, density functional theory, hydride vapor-phase epitaxy, ion radius, Raman spectrum.
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