为了开发出高效稳定的单一基质白光发射荧光材料，本工作通过高温固相法成功合成了一系列La₄GeO₈∶Bi³⁺，Eu³⁺荧光粉样品，并通过X射线衍射、室温光谱、变温光谱等手段研究了实验样品的结构与发光性能。研究发现，Bi³⁺离子在该结构中占据两种不同的格位（Bi³⁺（Ⅰ）和Bi³⁺（Ⅱ）），且在紫外光激发下呈现两个峰值分别在475 nm和620 nm的宽带发射。对于Bi³⁺、Eu³⁺共掺样品，由于Bi³⁺（Ⅰ）与Eu³⁺之间的竞争吸收、Bi³⁺（Ⅰ）至Bi³⁺（Ⅱ）以及Bi³⁺（Ⅱ）至Eu³⁺的能量传递作用，可实现蓝色至红色、橙红色至红色的可调发光。特别地，样品La₄GeO₈∶0.07Bi³⁺，0.06Eu³⁺在313 nm光激发下可获得CIE值为（0.335，0.319）的优异白色发光。此外，该白光发射材料具有较佳的发光热稳定性，当温度升高至380 K时，发光积分强度仍然为室温的59%，表明其在白光二极管上具有潜在的应用价值。

为了实现在无外部供能下对紫外光的有效探测，基于Ag修饰的Bi₂O₃纳米块（Ag/Bi₂O₃）纳米块制备了自供能紫外探测器。通过煅烧法制备Bi₂O₃纳米块，随后采用室温溶液法在其表面沉积Ag纳米粒子，进而成功制备了Ag/Bi₂O₃纳米块，且对所制备样品的晶体结构和微观形貌等进行了表征。结果表明，Ag/Bi₂O₃纳米块的平均尺寸约为1 μm，且Ag纳米粒子随机分布在Bi₂O₃纳米块表面。将涂覆Ag/Bi₂O₃纳米块的FTO作为工作电极，并进一步构建了自供能紫外探测器。在365 nm的紫外光照射下，Ag/Bi₂O₃纳米块紫外探测器能在零偏压下实现对紫外光的快速检测，这证实其具有自供能特性。相比于Bi₂O₃纳米块紫外探测器，Ag/Bi₂O₃纳米块紫外探测器的光电流得到明显提升，上升和下降时间分别缩短至29.1 ms和40.2 ms，并具有良好的循环稳定性。

Two-dimensional (2D) WSe₂ has received increasing attention due to its unique optical properties and bipolar behavior. Several WSe₂-based heterojunctions exhibit bidirectional rectification characteristics, but most devices have a lower rectification ratio. In this work, the Bi₂O₂Se/WSe₂ heterojunction prepared by us has a type Ⅱ band alignment, which can vastly suppress the channel current through the interface barrier so that the Bi₂O₂Se/WSe₂ heterojunction device has a large rectification ratio of about 10⁵. Meanwhile, under different gate voltage modulation, the current on/off ratio of the device changes by nearly five orders of magnitude, and the maximum current on/off ratio is expected to be achieved 10⁶. The photocurrent measurement reveals the behavior of recombination and space charge confinement, further verifying the bidirectional rectification behavior of heterojunctions, and it also exhibits excellent performance in light response. In the future, Bi₂O₂Se/WSe₂ heterojunction field-effect transistors have great potential to reduce the volume of integrated circuits as a bidirectional controlled switching device.

We demonstrate a high-performance acousto-optic modulator-based bi-frequency interferometer, which can realize either beating or beating free interference for a single-photon level quantum state. Visibility and optical efficiency of the interferometer are (99.5±0.2)% and (95±1)%, respectively. The phase of the interferometer is actively stabilized by using a dithering phase-locking scheme, where the phase dithering is realized by directly driving the acousto-optic modulators with a specially designed electronic signal. We further demonstrate applications of the interferometer in quantum technology, including bi-frequency coherent combination, frequency tuning, and optical switching. These results show the interferometer is a versatile device for multiple quantum technologies.

三价铋离子（Bi³⁺）是一种优良的发光材料激活剂和敏化剂，近年来得到了广泛研究。Bi³⁺离子发光易受晶体场强度的影响，在紫外和近紫外激发下可获得覆盖整个可见光区域的丰富发射颜色及近红外发光，因而受到广泛关注，同时相关发光材料在固态照明、显示、生物医学和光学传感方面显示出良好的应用前景。本综述总结了Bi³⁺的发光特点，重点阐述了几类Bi³⁺掺杂发光材料的研究进展，并详细介绍了其发光性质与晶体结构间的构?效关系。针对Bi³⁺掺杂发光材料的发光性能精准调控与优化的关键问题，本综述讨论了组分取代、能量传递、混合价态等设计策略诱导性能调控与优化的机理。最后，我们探讨了Bi³⁺掺杂发光材料研究未来的一些挑战和机遇，以期指导pc?LED应用中新型发光材料的开发。

晶粒细化是提高Bi_0.5Sb_1.5Te₃合金力学性能的有效途径, 但是粉末冶金过程中晶粒细化导致的类施主效应会严重劣化材料热电性能, 制约了Bi_0.5Sb_1.5Te₃基合金在微型热电器件中的应用。本研究围绕p型Bi_0.5Sb_1.5Te₃基合金, 采用实验结合理论计算系统研究了粉末冶金制备过程中研磨和脱附气氛对烧结样品中类施主效应和电热输运性能的影响规律和机制。Bi_0.5Sb_1.5Te₃基合金破碎研磨过程中粉体表面产生缺陷$~\text{V}_{\text{Te}}^{\cdot \cdot }$和${{\text{{V}'''}}_{\text{Sb}}}$并物理吸附空气中的O₂, 在烧结过程中与吸附的O₂发生缺陷化学反应, 产生大量$\text{V}_{\text{Te}}^{\cdot \cdot }$空位和自由电子, 导致类施主效应, 使空穴浓度大幅降低。在保护气氛下(Ar气氛)研磨避免接触空气或在空气中研磨后放置在保护气氛下脱附O₂, 都可以有效抑制类施主效应, 使样品保持较高的载流子浓度和电导率, 且性能在473 K下保持稳定。在空气中研磨后直接烧结的样品和放置在空气中粉体烧结的样品表现出明显的类施主效应, 样品的载流子浓度从保护气氛处理样品的4.49×10¹⁹ cm⁻³下降至3.21×10¹⁹ cm⁻³, 采用保护气氛处理的粉体烧结样品在402 K下获得最高的热电优值ZT为1.03, 平均ZT_ave为0.92。该研究为调控p型多晶Bi₂Te₃基化合物的类施主效应和优化其热电性能提供了新思路。