Significant advancements in nanoscale material efficiency optimization have made it feasible to substantially adjust the thermoelectric transport characteristics of materials. Motivated by the prediction and enhanced understanding of the behavior of two-dimensional (2D) bilayers (BL) of zirconium diselenide (ZrSe₂), hafnium diselenide (HfSe₂), molybdenum diselenide (MoSe₂), and tungsten diselenide (WSe₂), we investigated the thermoelectric transport properties using information generated from experimental measurements to provide inputs to work with the functions of these materials and to determine the critical factor in the trade-off between thermoelectric materials. Based on the Boltzmann transport equation (BTE) and Barden-Shockley deformation potential (DP) theory, we carried out a series of investigative calculations related to the thermoelectric properties and characterization of these materials. The calculated dimensionless figure of merit (ZT) values of 2DBL-MSe₂ (M = Zr, Hf, Mo, W) at room temperature were 3.007, 3.611, 1.287, and 1.353, respectively, with convenient electronic densities. In addition, the power factor is not critical in the trade-off between thermoelectric materials but it can indicate a good thermoelectric performance. Thus, the overall thermal conductivity and power factor must be considered to determine the preference of thermoelectric materials.Significant advancements in nanoscale material efficiency optimization have made it feasible to substantially adjust the thermoelectric transport characteristics of materials. Motivated by the prediction and enhanced understanding of the behavior of two-dimensional (2D) bilayers (BL) of zirconium diselenide (ZrSe₂), hafnium diselenide (HfSe₂), molybdenum diselenide (MoSe₂), and tungsten diselenide (WSe₂), we investigated the thermoelectric transport properties using information generated from experimental measurements to provide inputs to work with the functions of these materials and to determine the critical factor in the trade-off between thermoelectric materials. Based on the Boltzmann transport equation (BTE) and Barden-Shockley deformation potential (DP) theory, we carried out a series of investigative calculations related to the thermoelectric properties and characterization of these materials. The calculated dimensionless figure of merit (ZT) values of 2DBL-MSe₂ (M = Zr, Hf, Mo, W) at room temperature were 3.007, 3.611, 1.287, and 1.353, respectively, with convenient electronic densities. In addition, the power factor is not critical in the trade-off between thermoelectric materials but it can indicate a good thermoelectric performance. Thus, the overall thermal conductivity and power factor must be considered to determine the preference of thermoelectric materials.

Bilayer graphene, which is highly promising for electronic and optoelectronic applications because of its strong coupling of the Dirac–Fermions, has been studied extensively for the emergent correlated phenomena with magic-angle manipulation. Due to the low energy linear type band gap dispersion relationship, graphene has drawn an amount of optoelectronic devices applications in the terahertz region. However, the strong interlayer interactions modulated electron-electron and electron-phonon coupling, and their dynamics in bilayer graphene have been rarely studied by terahertz spectroscopy. In this study, the interlayer interaction influence on the electron-electron and the electron-phonon coupling has been assigned with the interaction between the two graphene layers. In the ultrafast cooling process in bilayer graphene, the interlayer interaction could boost the electron-phonon coupling process and oppositely reduce the electron-electron coupling process, which led to the less efficient thermalization process. Furthermore, the electron-electron coupling process is shown to be related with the electron momentum scattering time, which increased vividly in bilayer graphene. Our work could provide new insights into the ultrafast dynamics in bilayer graphene, which is of crucial importance for designing multi-layer graphene-based optoelectronic devices.

传统外延阻挡杂质带探测器由于其材料物性和特殊的结构设计存在很强的反射，这些能量损失非常不利于器件的探测性能。报道了一种类光栅双层超构表面微结构阵列，并将此人工微结构引入到外延阻挡杂质带红外探测器以抑制对入射光的反射。实验结果显示，具有超构表面微结构阵列的器件在波长30 μm处反射率低于3%，在25.3～32.2 μm波段范围内反射率低于20%。同时，该超表面减反微结构对入射光的偏振还具有很强的选择性，符合第四代焦平面发展需求。

In this Letter, Ti–Si bilayer was deposited on white silk to achieve coloration of the silk. By controlling the thickness of the Ti layer and Si layer, the saturation and the hue of the color on the silk could be preciously modulated, respectively. The structural colors on the silk could cover the major colors in the International Commission on Illumination 1931 chromaticity diagram, and it exhibits good durability, which is demonstrated by rubbing and stretching treatments. The developed textile coloration method may provide an eco-friendly technology in the silk dyeing industry.

提出一种多通道平面窄带滤光片阵列结构，该结构由双层金属光栅及其两侧的分布式布拉格反射器（DBRs）组成。所设计的多通道滤光片中心波长范围超过200 nm，每一个通道的中心波长可以通过调节光栅狭缝宽度来调节，从而实现多通道窄带滤光阵列。该结果为中波红外多通道窄带滤光片的设计提供了一条新的路径。