Unrelaxed State in Epitaxial Heterostructures Based on Lead Selenide

• 作者: Arif Pashaev Megi Enukashvili Omari Davarashvili Revaz Gulyaev Vladimir Zlomanov Zaira Akhvlediani
• 来源期刊: 现代物理(英文)
• 学科: 医学
• 关键词: MISMATCH LATTICE Constant STRAINED Layer Unrelaxed STATE Effective “Negative” Pressure Optical Characterization
• 年，卷（期）: 2012,（6）
• 页码范围: 502-510
• 页数: 9页
• 分类号: R73

摘要

The work deals with the epitaxial PbSe layers grown on the KCl substrates by the method of “hot-wall” molecular epitaxy over the range of layer thicknesses of 20 - 2000 nm. Special emphasis is put on the values of elastic deformations that could be generated and frozen in epitaxial layers with the aim of influencing their energy spectra and optical properties. The maximum deformation at layers tension made up 57% of the initial mismatch between the layer and the substrate (ε = Δa/a = 0.015). In such a solid-state structure effective “negative” pressure is realized, which is justified by increase in the tangential lattice constant and the forbidden gap width. This width correlates with the tangential lattice constant (deformation) and corresponds to certain values of definite frequencies of direct electron transitions across the forbidden gap.