Phase-change material (PCM) is widely used in thermal management due to their unique thermal behavior. However, related research in thermal rectifier is mainly focused on exploring the principles at the fundamental device level, which results in a gap to real applications. Here, we propose a controllable thermal rectification design towards building applications through the direct adhesion of composite thermal rectification material (TRM) based on PCM and reduced graphene oxide (rGO) aerogel to ordinary concrete walls (CWs). The design is evaluated in detail by combining experiments and finite element analysis. It is found that, TRM can regulate the temperature difference on both sides of the TRM/CWs system by thermal rectification. The difference in two directions reaches to 13.8 K at the heat flow of 80 W/m². In addition, the larger the change of thermal conductivity before and after phase change of TRM is, the more effective it is for regulating temperature difference in two directions. The stated technology has a wide range of applications for the thermal energy control in buildings with specific temperature requirements.

We introduce a novel method to create mid-infrared (MIR) thermal emitters using fully epitaxial, metal-free structures. Through the strategic use of epsilon-near-zero (ENZ) thin films in InAs layers, we achieve a narrow-band, wide-angle, and p-polarized thermal emission spectra. This approach, employing molecular beam epitaxy, circumvents the complexities associated with current layered structures and yields temperature-resistant emission wavelengths. Our findings contribute a promising route towards simpler, more efficient MIR optoelectronic devices.

针对高功率微波波形参数对限幅器温度分布特性的影响，基于双级PIN限幅器的场路协同仿真模型对微波脉冲幅值、频率对温度分布的影响展开了仿真研究。结果表明：微波脉冲幅值、频率的提升会使双级PIN限幅器中PIN二极管的高温区域分布向P区拓展、高温区域分布范围扩大；相对而言，微波脉冲幅值对温度分布的影响更为显著，频率对温度分布的影响相对较小。

大功率白光LED封装主要分为玻璃荧光片封装和荧光粉胶封装。本文提出一种用荧光胶封装大功率白光LED的方法，优化白光LED的发光面的均匀性，并分析了荧光胶封装和用荧光片封装的大功率白光LED的光热性能。实验结果表明，在1 400 mA电流驱动下，荧光胶封装白光LED的光通量为576.07 lm，比荧光片封装白光LED的光通量高15.5%，光转换效率为35.8%。在温度从25 ℃提升到125 ℃的过程中，荧光胶封装器件的亮度衰减了20%，色温从5 882.11 K提高到6 024.22 K。荧光胶封装的白光LED在常温下的热阻为1.7 K/W，与玻璃荧光片封装的热阻接近。在840 h高温高湿老化和1 600 h高温老化实验中，荧光胶封装的相对光衰均能稳定在97%。

近年来，近红外荧光粉转换发光二极管（NIR pc-LED）在夜视、生物成像和无损检测等领域引起了广泛关注。然而，获得兼具高量子效率和优异热稳定性的近红外荧光粉仍然是一个巨大挑战。本文利用高温固相法合成了一种新型近红外荧光粉BaY₂Al₂Ga₂SiO₁₂∶Cr³⁺（BYAGSO∶Cr³⁺），并系统研究了材料的结构和发光性质。在440 nm蓝光激发下，BYAGSO∶Cr³⁺荧光粉的发射光谱在650~850 nm范围内呈现锐线和宽带的混合发射，源于Cr³⁺：²E→⁴A₂自旋禁戒跃迁和⁴T₂→⁴A₂自旋允许跃迁发射。该近红外发光表现出可观的量子效率和良好的热稳定性，最优化样品的外量子效率可达30.3%，在200 ℃时样品的发光强度可保持其在室温时强度的99%。通过将BYAGSO∶Cr³⁺荧光粉与450 nm蓝光LED芯片结合，我们封装了一个NIR pc-LED器件。该器件在300 mA驱动电流下，输出功率为70.83 mW；在20 mA驱动电流下，光电转换效率为11.20%。研究结果表明，BYAGSO∶Cr³⁺在NIR pc-LED领域具有良好的应用前景。

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。