Fifteen periods of Si/Si_0.7Ge_0.3 multilayers (MLs) with various SiGe thicknesses are grown on a 200 mm Si substrate using reduced pressure chemical vapor deposition (RPCVD). Several methods were utilized to characterize and analyze the ML structures. The high resolution transmission electron microscopy (HRTEM) results show that the ML structure with 20 nm Si_0.7Ge_0.3 features the best crystal quality and no defects are observed. Stacked Si_0.7Ge_0.3 ML structures etched by three different methods were carried out and compared, and the results show that they have different selectivities and morphologies. In this work, the fabrication process influences on Si/SiGe MLs are studied and there are no significant effects on the Si layers, which are the channels in lateral gate all around field effect transistor (L-GAAFET) devices. For vertically-stacked dynamic random access memory (VS-DRAM), it is necessary to consider the dislocation caused by strain accumulation and stress release after the number of stacked layers exceeds the critical thickness. These results pave the way for the manufacture of high-performance multivertical-stacked Si nanowires, nanosheet L-GAAFETs, and DRAM devices.

In this study, CdO/Cu/CdO multilayers thin films were organized on glass substrates with different Cu intermetallic layer thickness engaging DC plasma magnetron sputtering. The optoelectronic properties and structural characteristics of the multilayers at various Cu intermetallic layer thicknesses which were varied from 4 to 16 nm were explored. The calculated band gap was reduced from 2.66 eV to 2.48 eV as the Cu intermetallic layer thickness increased from 4 to 16 nm. The refractive index and coefficient of extinction of CdO/Cu/CdO multilayers increased with increasing the Cu intermetallic layer thickness. The resistivity is reduced from 1.8 × 10⁻² Ω cm for CdO single layer to reach a value of 2.7 × 10⁻⁴ Ω cm for CdO/Cu (16 nm)/CdO multilayer. Further, the sheet resistance is decreased from 1000 to 13.8 Ω/sq. with the variation in Cu intermetallic layer thickness from 0 to 16 nm. CdO/Cu (4 nm)/CdO multilayer film recorded the best figure of merit (2.3 × 10⁻⁴ Ω⁻¹). After sunlight illumination for the multilayers, the surface wettability was improved and the contact angle recorded lowest value of nearly 24° for CdO/Cu (8 nm)/CdO and CdO/Cu (12 nm)/CdO.

为研究本底真空对Yb/Al多层膜微结构和光学性能的影响，使用直流磁控溅射设备，在本底真空度分别为4×10^-5 Pa、8×10^-5 Pa、1×10^-4 Pa、2×10^-4 Pa和4×10^-4 Pa条件下，制备了一组结构相同的SiC/（Yb/Al）₃周期多层膜。使用X射线掠入射反射、原子力显微镜及大角X射线衍射等方法表征了样品表面和内部结构，结果表明：当本底真空度从4×10^-4 Pa提高至4×10^-5 Pa时，Yb/Al多层膜的平均界面宽度从2.15 nm减小到1.82 nm；表面粗糙度从1.87 nm减小到1.43 nm；膜层内有Yb、Yb₂O₃和Al结晶，结晶尺寸随真空度略有增加。SiC/（Yb/Al）₃周期多层膜为张应力，当本底真空度从4×10^-4 Pa提升至4×10^-5 Pa时，应力从85 MPa增大到142 MPa。测试了本底真空度为4×10^-5 Pa时制备的多层膜样品的反射率，在波长为73.6 nm、入射角为5°时，反射率为31.3%。

The effect of material dispersion on the optical properties of one-dimensional non-Hermitian scattering systems is investigated in detail. In particular, multilayer heterostructures with gain and loss (parity-time symmetric or not) are examined by taking into account the dispersion of each layer. The exceptional points and phase transitions are characterized based on the spectrum of the corresponding scattering matrix. We demonstrate that an on-average lossy heterostructure can amplify an incident plane wave in the frequency range associated with the emission frequency of the layer with gain.

Multiple resonant excitations of surface plasmons in a graphene stratified slab are realized by Otto configuration at terahertz frequencies. The proposed graphene stratified slab consists of alternating dielectric layers and graphene sheets, and is sandwiched between a prism and another semi-infinite medium. Optical response and field distribution are determined by the transfer matrix method with the surface current density boundary condition. Multiple resonant excitations appear on the angular reflection spectrum, and are analyzed theoretically via the phase-matching condition. Furthermore, the effects of the system parameters are investigated. Among them, the Fermi levels can tune the corresponding resonances independently. The proposed concept can be engineered for promising applications, including angular selective or multiplex filters, multiple channel sensors, and directional delivery of energy.