Lead telluride and germanium telluride are well-known IV-VI semiconductors, which is now the focus of research due to the perspective of application as thermoelectrics for midrange temperatures. Solid solutions and heterostructures on this basis, obtained by molecular beam epitaxy, are a promising direction for the development of these materials. In this paper, we have focused on the Raman spectra excited by the 514.5 nm laser line (out of resonance) of PbTe, GeTe, (Pb, Ge)Te, and (Pb, Ge, Eu)Te layers grown on BaF₂ (111) monocrystalline substrates. The obtained phonon properties are related to the properties of the corresponding bulk materials or can be explained by a model that takes into account the difference in the masses of the constituent elements only, as is the case with the local mode of Ge in PbTe (registered at about 181 cm⁻¹). Multiphonon processes registered for this phonon are a consequence of the change in the electronic structure of PbTe and electron-phonon interaction. An improvement in the quality of thin films due to doping with Eu ions was also registered.

中文翻译：

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PbTe 和 GeTe 基单晶外延层的拉曼光谱

碲化铅和碲化锗是众所周知的IV-VI族半导体，由于作为中温热电材料的应用前景，它们现在成为研究的焦点。在此基础上通过分子束外延获得的固溶体和异质结构是这些材料发展的一个有前途的方向。_{在本文中，我们重点研究了在 BaF 2}上生长的 PbTe、GeTe、(Pb, Ge)Te 和 (Pb, Ge, Eu)Te 层的 514.5 nm 激光线（非共振）激发的拉曼光谱（ 111) 单晶衬底。获得的声子性质与相应块体材料的性质相关，或者可以通过仅考虑组成元素质量差异的模型来解释，就像 PbTe 中 Ge 的局域模式（已注册在约181cm ^-1 )。该声子记录的多声子过程是 PbTe 电子结构变化和电子-声子相互作用的结果。由于掺杂了 Eu 离子，薄膜的质量也得到了改善。