Timofeev Vyacheslav, Nikiforov Alexandr, Tuktamyshev Artur, Mashanov Vladimir, Yesin Michail, Bloshkin Aleksey
A.V. Rzhanov Institute of Semiconductor Physics SB RAS, 13 Lavrentyev Avenue, Novosibirsk, 630090, Russia.
National Research Tomsk Polytechnical University, 36 Lenin Avenue, Tomsk, 634050, Russia.
Nanoscale Res Lett. 2018 Jan 19;13(1):29. doi: 10.1186/s11671-017-2429-6.
The dependences of the two-dimensional to three-dimensional growth (2D-3D) critical transition thickness on the composition for GeSiSn films with a fixed Ge content and Sn content from 0 to 16% at the growth temperature of 150 °С have been obtained. The phase diagrams of the superstructure change during the epitaxial growth of Sn on Si and on Ge(100) have been built. Using the phase diagram data, it becomes possible to identify the Sn cover on the Si surface and to control the Sn segregation on the superstructure observed on the reflection high-energy electron diffraction (RHEED) pattern. The multilayer structures with the GeSiSn pseudomorphic layers and island array of a density up to 1.8 × 10 cm have been grown with the considering of the Sn segregation suppression by the decrease of GeSiSn and Si growth temperature. The double-domain (10 × 1) superstructure related to the presence of Sn on the surface was first observed in the multilayer periodic structures during Si growth on the GeSiSn layer. The periodical GeSiSn/Si structures demonstrated the photoluminescence in the range of 0.6-0.85 eV corresponding to the wavelength range of 1.45-2 μm. The calculation of the band diagram for the structure with the pseudomorphic GeSiSn layers allows assuming that photoluminescence peaks correspond to the interband transitions between the X valley in Si or the Δ-valley in GeSiSn and the subband of heavy holes in the GeSiSn layer.
已获得在150℃生长温度下，固定Ge含量且Sn含量从0到16%的GeSiSn薄膜的二维到三维生长（2D-3D）临界转变厚度随成分的依赖关系。构建了Sn在Si以及Ge(100)上外延生长过程中超结构的相图。利用相图数据，能够识别Si表面的Sn覆盖情况，并控制在反射高能电子衍射（RHEED）图案上观察到的超结构上的Sn偏析。通过考虑降低GeSiSn和Si生长温度来抑制Sn偏析，生长出了具有GeSiSn赝配层和密度高达1.8×10¹⁰cm⁻²的岛阵列的多层结构。在GeSiSn层上生长Si的过程中，首次在多层周期性结构中观察到与表面存在Sn相关的双畴（10×1）超结构。周期性的GeSiSn/Si结构在0.6 - 0.85 eV范围内表现出光致发光，对应于1.45 - 2μm的波长范围。对具有赝配GeSiSn层的结构的能带图计算表明，光致发光峰对应于Si中的X谷或GeSiSn中的Δ谷与GeSiSn层中的重空穴子带之间的带间跃迁。
