Formation of nano-size Cr layers on LiNbO$_3$ crystal surfaces by dissimilar electric charges

The screening effects influence on the nano-domain tailoring in ferroelectrics-semiconductors

We calculate the realistic sizes of nano-domains recorded by the electric field of atomic force microscope tip in BaTiO3 and LiNbO3 ferroelectric-semiconductors in contrast to the over-estimated ones obtained in the previous works. We modified the existing models of domain formation allowing for the Debye screening, recharging of sluggish surface screening layers caused by emission current between the tip apex and the domain butt surface and the redistribution of domain depolarization field induced by the charged tip apex. We have shown that the depolarization field energy of the domain butt, …

A new physical simulation tool to predict the interface of dissimilar aluminum to steel welds performed by Friction Melt Bonding

Optimization of the intermetallic layer thickness and the suppression of interfacial defects are key elements to improve the load bearing capacity of dissimilar joints. However, till date we do not have a systematic tool to investigate the dissimilar joints and the intermetallic properties produced by a welding condition. Friction Melt Bonding (FMB) is a recently developed technique for joining dissimilar metals that also does not exempt to these challenges. The FMB of DP980 and Al6061-T6 is investigated using a new physical simulation tool, based on Gleeble thermo-mechanical simulator, to und…

On-demand Plasmon Nanoparticle-Embedded Laser-Induced Periodic Surface Structures (LIPSSs) on Silicon for Optical Nanosensing

Ultrashort laser pulses allows to deliver electromagnetic energy to matter causing its localized heating that can be used for both material removal via ablation/evaporation and drive interface chemical reactions. Here, we showed that both mentioned processes can be simultaneously combined within straightforward laser nanotexturing of Si wafer in functionalizing solution to produce a practically relevant metal-semiconductor surface nano-morphology. Such unique hybrid morphology represent deep-subwavelength Si LIPSSs with a extremely short period down to 70 nm with their high-aspect-ratio nanotr…

一种用于预测金属颗粒表面能与形状的基于配位的模型

A Coordination-Based Model for the Prediction of Surface Energies and the Shape of Metal Particles

本研究提出一种基于配位数的金属基体系能量预测模型，经后过渡金属DFT计算验证，无需DFT即可实时预测表面能并实现任意原子数金属颗粒的Wulff构造，分层优化后精度提升，可为纳米颗粒表面分布与稳定性研究提供有效支撑。

Design Principles and Physical Properties of Two-Dimensional Heterostructured Borides

Principles of design to create dynamically stable transition metal, lanthanide, and actinide based low-dimensional borides are presented. A charge transfer analysis of donor metal atoms to electron deficient honeycombed B lattices allows to predict complex covalent heterostructures hosting Dirac states. The applicable guidelines are supported with the analysis of phonon spectra computed with first-principles calculations to demonstrate the physical stability of nanometer-thick heterostructures. Similar or dissimilar layered borides can be stacked on top of each other in a layer-by-layer fashio…

光致发光探测铁电畴壁上 MoS2 p-n 结的热释电掺杂反转

Pyroelectric doping reversal of MoS2 p-n junctions on ferroelectric domain walls probed by photoluminescence

本研究利用空间分辨光致发光揭示周期性极化 LiNbO3 的热释电电荷可无栅极调控单层 MoS2 掺杂，并在冷却时反转畴壁 p-n 结为 n-p 结。

Exciton-Plasmon Coupling in 2D Semiconductors by Surface Acoustic Waves

We theoretically demonstrate the coupling between excitons in 2D semiconductors and surface plasmons in a thin metal film by means of a surface acoustic wave (SAW), proving that the generated exciton-plasmon polaritons (or plexcitons) are in the strong coupling regime. The strain field of the SAW creates a dynamic diffraction grating providing the momentum match for the surface plasmons, whereas the piezoelectric field, that could dissociate the excitons, is cancelled out by the metal. This is exemplified for monolayer MoS$\mathrm{_{2}}$ and mono- and few-layer black phosphorus on top of a thi…

Electronic structure, charge transfer, and intrinsic luminescence of gadolinium oxide nanoparticles: Experiment and theory

The cubic (c) and monoclinic (m) polymorphs of Gd2O3 were studied using the combined analysis of several materials science techniques - X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. Density functional theory (DFT) based calculations for the samples under study were performed as well. The cubic phase of gadolinium oxide (c-Gd2O3) synthesized using a precipitation method exhibits spheroidal-like nanoclusters with well-defined edges assembled from primary nanoparticles with an average size of 50 nm, wh…

设计非对称过渡金属二硫化物异质结构中的三维电子能带

Designer three-dimensional electronic bands in asymmetric transition metal dichalcogenide heterostructures

本研究通过异质结构设计，在三维中实现了非对称过渡金属二硫化物的电子能带调控，揭示了层间耦合与拓扑相稳定的新机制。

采用H$_2$和SF$_6$等离子体顺序曝光的MgO掺杂铌酸锂各向同性原子层刻蚀

Isotropic atomic layer etching of MgO-doped lithium niobate using sequential exposures of H$_2$ and SF$_6$ plasmas

针对薄膜铌酸锂器件因表面粗糙度导致性能受限的问题，提出基于多种等离子体顺序曝光的各向同性原子层刻蚀工艺，可有效降低波导侧壁粗糙度，提升集成光子器件性能。