The performance and reliability of ferroelectric thin films at temperatures around a few Kelvin are critical for their application in cryo-electronics. In this work, TiN/Hf_0.5Zr_0.5O₂/TiN capacitors that are free from the wake-up effect are investigated systematically from room temperature (300 K) to cryogenic temperature (30 K). We observe a consistent decrease in permittivity (ε_r) and a progressive increase in coercive electric field (E_c) as temperatures decrease. Our investigation reveals exceptional stability in the double remnant polarization (2P_r) of our ferroelectric thin films across a wide temperature range. Specifically, at 30 K, a 2P_r of 36 μC/cm² under an applied electric field of 3.0 MV/cm is achieved. Moreover, we observed a reduced fatigue effect at 30 K in comparison to 300 K. The stable ferroelectric properties and endurance characteristics demonstrate the feasibility of utilizing HfO₂ based ferroelectric thin films for cryo-electronics applications.

Mn离子掺杂策略被广泛用于提高CsPbX₃钙钛矿纳米晶（Nanocrystals，NCs）的稳定性和调控Pb的含量，但离子掺杂反应速率极快，不易控制。本文分别采用一步和两步热注射法对Mn²⁺的掺杂含量进行大范围和精确调控，制备出具有不同Mn²⁺掺杂含量的CsPbCl₃∶Mn²⁺ NCs。通过对其结构及发光性能的研究，将其区分为合金结构和掺杂结构，并进一步揭示了一步法和两步法进行Mn²⁺调控时的不同机制，明确了在相同Pb∶Mn投料比的情况下，一步法合成的合金结构纳米晶具有更高的Mn²⁺掺杂量，使得纳米晶在610 nm左右与Mn相关的发射峰更为强烈，最高光致发光量子产为77%，而两步法合成的掺杂结构纳米晶在较少的Mn²⁺情况下同样具有较高的光致发光量子产率。同时，Mn²⁺的可控掺杂使得钙钛矿纳米晶的稳定性有效提升，放置四周后形貌和发光性能仍稳定。值得注意的是，合金结构对于本征激子发光稳定性的提升比掺杂结构更加有利。此外，还合成了具有优异发光性能的CsPb（Cl_xBr_3-x）∶Mn²⁺钙钛矿纳米晶，其荧光光谱可在404～640 nm之间调控；但当Br^-含量较高时，与Mn相关的发射峰消失，这是由于CsPbBr₃的能带与Mn²⁺的⁴T₁-⁶A₁能级不匹配所致。本文强调了在CsPbCl₃∶Mn²⁺钙钛矿制备过程中Mn²⁺可控掺杂的重要性，对于实现纳米晶的可控合成具有重要意义。

As typical quarternary copper-based chalcogenides, Cu–Zn–Sn–S nanocrystals (CZTS NCs) have emerged as a new-fashioned electrocatalyst in hydrogen evolution reactions (HERs). Oleylamine (OM), a reducing surfactant and solvent, plays a significant role in the assisting synthesis of CZTS NCs due to the ligand effect. Herein, we adopted a facile one-pot colloidal method for achieving the structure evolution of CZTS NCs from 2D nanosheets to 1D nanorods assisted through the continuous addition of OM. During the process, the mechanism of OM-induced morphology evolution was further discussed. When merely adding pure 1-dodecanethiol (DDT) as the solvent, the CZTS nanosheets were obtained. As OM was gradually added to the reaction, the CZTS NCs began to grow along the sides of the nanosheets and gradually shrink at the top, followed by the formation of stable nanorods. In acidic electrolytic conditions, the CZTS NCs with 1.0 OM addition display the optimal HER activity with a low overpotential of 561 mV at 10 mA/cm² and a small Tafel slope of 157.6 mV/dec compared with other CZTS samples. The enhancement of HER activity could be attributed to the contribution of the synergistic effect of the diverse crystal facets to the reaction.

This letter showcases the successful fabrication of an enhancement-mode (E-mode) buried p-channel GaN field-effect-transistor on a standard p-GaN/AlGaN/GaN-on-Si power HEMT substrate. The transistor exhibits a threshold voltage (V_TH) of ?3.8 V, a maximum ON-state current (I_ON) of 1.12 mA/mm, and an impressive I_ON/I_OFF ratio of 10⁷. To achieve these remarkable results, an H plasma treatment was strategically applied to the gated p-GaN region, where a relatively thick GaN layer (i.e., 70 nm) was kept intact without aggressive gate recess. Through this treatment, the top portion of the GaN layer was converted to be hole-free, leaving only the bottom portion p-type and spatially separated from the etched GaN surface and gate-oxide/GaN interface. This approach allows for E-mode operation while retaining high-quality p-channel characteristics.

锂硫电池(LSBs)因能量密度高、原料储量丰富、环境友好等优点引起了广泛关注。然而, 多硫化物的穿梭效应、反应过程中较大的体积膨胀以及硫较差的电子电导率等缺点极大地限制了其发展。本研究设计了一种SnS₂纳米颗粒与ZIF-8衍生的花状二维多孔碳纳米片/硫复合材料(ZCN-SnS₂-S), 并研究了其作为锂硫电池正极的电化学性能。其独特的二维花状多孔结构不仅有效缓解了反应过程中的体积膨胀, 而且为Li⁺和电子的传输提供了快速通道, 杂原子N也促进了对多硫化物的吸附作用。并且负载的极性SnS₂纳米颗粒极大地增强了对多硫化物的吸附, 从而使ZCN-SnS₂-S复合材料表现出优异的电化学性能。在0.2C(1C=1675 mA·g^-1)电流密度下, ZCN-SnS₂-S电极循环100次后仍能保持948 mAh·g^-1的高可逆比容量, 容量保持率为83.7%。即使在2C的高电流密度下循环300圈, ZCN-SnS₂-S电极仍具有546 mAh·g^-1的可逆比容量。

能量分辨中子成像谱仪是中国散裂中子源当前在建的谱仪之一，其衍射探测器90°分区采用⁶LiF/ZnS中子闪烁体探测器作为探测设备。为实现探测器高位置分辨，读出电子学系统采用了一种电容网络复合读出电路和电荷重心法相结合的实现方法，并研制了电子学样机。该样机由电容网络复合读出电路、前置放大板和数字读出板三部分组成，基本功能验证完成后，分别在实验室和中国散裂中子源的20号束线上进行了相关性能参数测试，测试结果显示：电子学的积分非线性≤0.95%，时间分辨约为12 ns；探测器位置分辨为1 mm、探测效率为65%@1.6 ?，均达到了工程设计指标。该样机的成功研制为能量分辨中子成像谱仪未来顺利开展谱仪实验提供了可靠的技术保障。

高速光探测器以获得更高的3 dB带宽为目标，减小器件台面面积能够使结电容降低从而提高带宽，但同时也增大了系统中的光耦合损耗。针对该问题，在高速光探测器衬底背面单片集成微透镜结构是一种有效的解决方案，该结构可通过补偿对准偏差来提高器件的光耦合效率。设计了一种面向数据中心应用的，与1.31 μm光探测器芯片单片集成的InP基微透镜结构；通过热熔法制作微透镜胶型，并利用电感耦合等离子体刻蚀实现微透镜胶型转移，电感耦合等离子体刻蚀过程选择SiCl₄和Ar作为刻蚀气体以保证实验的安全性；制备了一种直径90.3 μm、冠高18.5 μm、表面形貌光滑的InP基微透镜结构。单片集成微透镜的PIN光探测器在1.31 μm波长处，入射光偏离主光轴3°的情况下，光探测器的响应度仅下降4%。