Applications of cesium in the perovskite solar cells

Perovskite solar cells have experienced an unprecedented rapid development in the power conversion efficiency (PCE) during the past 7 years, and the record PCE has been already comparable to the traditional polycrystalline silicon solar cells. Presently, it is more urgent to address the challenge on device stability for the future commercial application. Recently, the inorganic cesium lead halide perovskite has been intensively studied as one of the alternative candidates to improve device stability through controlling the phase transition. The cesium (Cs)-doped perovskites show more superior stability comparing with organic methylammonium (MA) lead halide perovskite or formamidinium (FA) lead halide perovskite. Here, recent progress of the inorganic cesium application in organic-inorganic perovskite solar cells (PSCs) is highlighted from the viewpoints of the device efficiency and the device stability.     

锂云母复合盐焙烧-水浸提取锂铷铯

采用复合盐焙烧-水浸工艺从锂云母中提取锂、铷、铯,研究了焙烧工艺参数及浸出工艺参数对锂、铷、铯浸出率的影响。结果表明,锂云母精矿焙烧时,复合盐焙烧效果优于单一盐添加剂,CaCl₂+Na₂CO₃组合添加剂具有焙烧时氯气排放少、焙烧矿浸出效果好等优点。从锂云母中回收锂、铷、铯,较佳的焙烧-浸出工艺条件为: CaCl₂+Na₂CO₃组合为焙烧添加剂,锂云母精矿∶CaCl₂∶Na₂CO₃(质量比)=1∶0.5∶0.2,锂云母精矿焙烧温度900 ℃、焙烧时间2 h,对焙烧矿进行室温水浸,浸出时间1 h、液固比2∶1,此时锂、铷、铯浸出率分别为86.64%、92.58%、85.37%。含锂浸出液经2次调节pH值净化除钙,升温至95 ℃后加入饱和Na₂CO₃溶液,结晶得到碳酸锂,样品纯度为99.08％,产品纯度及杂质含量达到一级碳酸锂标准。沉锂母液采用溶剂萃取法分离铷、铯,铯萃取率达到99%以上,铷洗脱率达到96%左右。     

无机离子交换剂去除放射性废水中~(137)Cs的研究进展

无机离子交换剂凭借其独特的物理化学性能,及其在去除放射性废水中137Cs的突出表现,引起人们的广泛关注。概述了硅铝酸盐、杂多酸盐、亚铁氰化物、不溶性多价金属酸性盐、不溶性多价金属水合氧化物、钛硅酸盐等不同类型无机离子交换剂去除放射性废水中137Cs的研究进展,介绍了无机离子交换剂去除放射性废水中137Cs的典型应用,以期为我国放射性废水的处理及处置提供借鉴。     

Dependence of Light‐Emitting Characteristics of Blue Phosphorescent Organic Light‐Emitting Diodes on Electron Injection and Transport Materials

We investigate the light‐emitting performances of blue phosphorescent organic light‐emitting diodes (PHOLEDs) with three different electron injection and transport materials, that is, bathocuproine(2,9‐dimethyl‐4,7‐diphenyl‐1,10‐phenanthroline) (Bphen), 1,3,5‐tri(m‐pyrid‐3‐yl‐phenyl)benzene (Tm3PyPB), and 2,6‐bis(3‐(carbazol‐9‐yl)phenyl)pyridine (26DCzPPy), which are partially doped with cesium metal. We find that the device characteristics are very dependent on the nature of the introduced electron injection layer (EIL) and electron transporting layer (ETL). When the appropriate EIL and ETL are combined, the peak external quantum efficiency and peak power efficiency improve up to 20.7% and 45.6 lm/W, respectively. Moreover, this blue PHOLED even maintains high external quantum efficiency of 19.6% and 16.9% at a luminance of 1,000 cd/m² and 10,000 cd/m², respectively.     

小型磁选态铯束管的抗振动性能研究

分析了铯束管的固有振动特性,得出了铯束管的危险共振频率和结构的薄弱环节,提出了相应的振动加固措施,这些加固措施可以应用到空间铯束管的研制中。设计了铯束管的正弦扫频试验,通过试验结果与仿真结果之间的对比,验证了有限元模型的合理性和有限元分析的精度。     

Investigation of LSPR Coupling Effects toward the Rational Design of CsxWO3–δ Based Solar NIR Filtering Coatings

The optical range of localized surface plasmon resonance (LSPR) is extended into the infrared region, thanks to the development of highly doped semiconductor nanocrystals. Particularly, the near-infrared (NIR) range holds a significant interest in managing solar radiation. However, practical applications necessitate the arrangement of particles, which is known to possibly impact their optical properties through LSPR coupling effects. How such coupling modifies the LSPR response in semiconductor hosts remains largely unexplored. In this study, a protocol for producing composite coatings composed of cesium-doped tungsten bronze nanocrystals embedded in a silica matrix is presented. Achieving individual dispersion of nanocrystals is made possible through careful selection of a surface polyglycerol ligand exchange. This allows to tune the interparticle distance by adjusting the nanocrystal volume fraction in the composite. The findings demonstrate that LSPR coupling effects significantly influence the LSPR intensity of nanocrystals in the composite when the nanocrystal-to-nanocrystal distance matches their size. Beyond elucidating the LSPR coupling effect, this study provides insights into the potential use of Cs-HTB nanocrystals for solar control applications. Through the optimization of morphology and film structure, remarkable selectivity is obtained in terms of maintaining good transparency in the visible range while achieving high absorption in the NIR.     

Stabilizing Bottom Side of Perovskite via Preburying Cesium Formate toward Efficient and Stable Solar Cells

The fragile bottom side of perovskite films is demonstrated to be harmful to the efficiency and stability of perovskite solar cells (PSCs) because the carrier extraction and recombination can be significantly influenced by the easily formed strain, voids, and defects on the bottom side. Nevertheless, the bottom side of perovskite films is usually overlooked because it remains a challenge to directly characterize and modify the bottom side. Herein, a facile and effective strategy is reported to stabilize the bottom side via preburying cesium formate (CsFo) into the SnO₂ electron transport layer (ETL). It is found that the synergistic effect of cesium cation (Cs⁺) and formate anion (HCOO⁻) causes strain relaxation, void elimination, and defects’ reduction, which further facilitate the charge extraction. Consequently, the champion power conversion efficiency (PCE) of formamidinium (FA)-based PSCs is increased from 23.34% to 24.50%. Meanwhile, the ultraviolet (UV), thermal, and operational stability are also enhanced. Finally, formamidinium–cesium (FACs)-based PSCs are investigated to confirm the effectiveness of this preburied CsFo strategy, and the optimal device exhibits a champion PCE of 25.03% and a remarkably high fill factor (FF) of 85.65%.     

铯喷泉钟C场的测量与计算

在铯原子喷泉钟实验中，C场均匀度决定了二阶塞曼频移的不确定度评定。使用微波激励法可以测量C场各个高度经时间加权的磁感应强度的平均值。为了得到C场的实际磁场分布，需要对微波激励法的测量结果进行去时间加权计算。介绍了两种去时间加权的算法，并利用仿真数据对算法进行了验证。最后使用微波激励法和两种去时间加权算法，结合蒙特卡洛不确定度评定方法对NIM6铯喷泉钟C场进行了测量与计算。     

电感耦合等离子体质谱法测定模拟玻璃固化体中Cs2O的含量

建立了一种电感耦合等离子体质谱法（ICP-MS）测定玻璃固化体中铯含量的方法。该方法从ICP-MS的背景控制、内标物选择、质谱干扰等方面进行了优化。试验结果表明，该方法检出限为0.18mg/kg，相对标准偏差（n=12）为0.48%～4.11%，加标回收率为98%～102%，可用于玻璃固化体中铯含量的测定。     

Highly-Stable CsPbI3 Perovskite Solar Cells with an Efficiency of 21.11% via Fluorinated 4-Amino-Benzoate Cesium Bifacial Passivation

The poor interface quality between cesium lead triiodide (CsPbI₃) perovskite and the electron transport layer limits the stability and efficiency of CsPbI₃ perovskite solar cells (PSCs). Herein, a 4-amino-2,3,5,6-tetrafluorobenzoate cesium (ATFC) is designed as a bifacial defect passivator to tailor the perovskite/TiO₂ interface. The comprehensive experiments demonstrate that ATFC can not only optimize the conductivity, electron mobility, and energy band structure of the TiO₂ layer by passivation of the undercoordinated Ti⁴⁺, oxygen vacancy (V_O), and free  OH defects but also promote the yield of high-quality CsPbI₃ film by synergistic passivation of undercoordinated Pb²⁺ defects with the  CO group and F atom, and limiting I⁻ migration via F···I interaction. Benefiting from the above interactions, the ATFC-modified CsPbI₃ device yields a champion power conversion efficiency (PCE) of 21.11% and an excellent open-circuit voltage (V_OC) of 1.24 V. Meanwhile, the optimized CsPbI₃ PSC maintains 92.74% of its initial efficiency after aging 800 h in air atmosphere, and has almost no efficiency attenuation after tracking at maximum power point for 350 h.