Side‐Chain Engineering on Dopant‐Free Hole‐Transporting Polymers toward Highly Efficient Perovskite Solar Cells (20.19%)

A variety of dopant‐free hole‐transporting materials (HTMs) is developed to serve as alternatives to the typical dopant‐treated ones; however, their photovoltaic performance still falls far behind. In this work, the side chain of a polymeric HTM is engineered by partially introducing diethylene glycol (DEG) groups in order to simultaneously optimize the properties of both the bulk of the HTM layer and the HTM/perovskite interface. The intermolecular π–π stacking interaction in the HTM layer is unexpectedly weakened after the incorporation of DEG groups, whereas the lamellar packing interaction is strengthened. A doubled hole mobility is obtained when 3% of the DEG groups replace the original alkyl side chains, and a champion power conversion efficiency (PCE) of 20.19% (certified: 20.10%) is then achieved, which is the first report of values over 20% for dopant‐free organic HTMs. The device maintains 92.25% of its initial PCE after storing at ambient atmosphere for 30 d, which should be due to the enhanced hydrophobicity of the HTM film.     

高炉开炉装料计算软件的设计

高炉开炉装料计算工作繁琐、复杂,手工计算耗费时间长、容易出错,难以得到最佳方案,影响高炉顺利开炉。通过高炉开炉装料计算软件的开发实践,介绍了装料计算模型的建模步骤;讨论了软件的功能需求;阐述了选用三层网络结构的原因,从而描述了装料计算软件的设计方法。软件投入运行后,能够快速、准确地计算、分析开炉数据,取得了满意的效果。     

宽带数字单边带下变频器

数字单边带下变频器是软件无线电中不可缺少的组成部分,也是射电观测中,数据采集设备的重要组成部分,由于该模块紧接高速A/D采样器之后,所以对其运算处理能力有很高的要求.本文提出了实现宽带数字单边带下变频器的一种可行方案——并行处理,可以从根本上解决数字信号处理的瓶颈效应.     

Voltage difference engineering in SOI MOSFETs: A novel side gate device with improved electrical performance

We studied the impact of voltage difference engineering in a silicon-on-insulator metal oxide semiconductor field-effect transistor (SOI-MOSFET) and compared the performance to that of a conventional SOI-MOSFET (C-SOI). Our structure, called a SIG-SOI MOSFET, includes main and side gates with an optimum voltage difference between them. The voltage difference leads to an inverted channel as an electrical drain extension under the side gate. This channel creates a stepped potential distribution along the channel that it cannot be seen in the C-SOI MOSFETs. The voltage difference controls the channel properly and two-dimensional two-carrier device simulations revealed lower threshold voltage variations, larger breakdown voltage, higher voltage gain, lower hot carrier effects, improved drain-induced barrier lowering, lower drain conductance, higher unilateral power gain, and lower leakage current compared to a C-SOI device. Thus, our proposed structure has higher performance than a typical C-SOI structure.     

探讨单侧下回风局部百级洁净区的影响因素

本文运用CFD技术以疫苗车间接毒无菌室为例,探讨了干扰采用FFU单侧下回风形式的局部百级洁净区流场的各种因素和影响程度,这对类似局部百级洁净区的优化设计具有较重要的理论意义与工程应用价值。     

Efficient Polymer Solar Cells with a High Open Circuit Voltage of 1 Volt

A series of polymers containing benzo[1,2‐b:4,5‐b′]dithiophene and N‐alkylthieno[3,4‐c]pyrrole‐4,6‐dione are designed. By incorporating different alkylthienyl side chains, the fill factor (FF) and open circuit voltage (V_oc) of the copolymers are further improved. The experimental results and theoretical calculations show that the size and topology of the side chains can influence the polymer solubility, energy levels, and intermolecular packing by altering the molecular coplanarity. As a result of improved morphology and fine‐tuned energy levels, an increased FF and a high V_oc of 1.00 V are achieved, as well as a power conversion efficiency of 6.17%, which is the highest efficiency ever reported for polymer solar cells with a V_oc over 1 V.     

直列式爆轰点火器起爆过程实验与数值仿真

为了探讨爆轰快速点火的特性,依据工程应用的实际情况,利用直列式起爆器设计了直列式爆轰点火器及实验装置,并进行了相关实验研究.结合实验装置的特殊结构,建立了直列式爆轰点火器起爆过程的理论计算模型,应用4阶龙格-库塔法编程计算得出爆轰冲击波在实验装置内传播过程中各物性参数的变化规律,并结合实验测试结果进行了分析.结果表明,在直列式爆轰点火结构设计中,利用突扩截面可以显著衰减冲击波的强度,减弱对点火过程的影响,有利于装药的全面、瞬时点火.     

主动围压和爆炸加载作用下岩石动态响应研究

为了研究爆炸冲击下深部岩石的破碎过程,建立主动围压约束及中心孔爆炸加载实验装置,利用动态测试技术、高速摄像和数字图像相关方法,得到动静组合加载下岩石内部的应变场和表面裂纹扩展过程。基于Johnson-Holmquist本构模型,对不同围压下岩石爆炸动态响应进行了模拟研究。对比结果发现：围压在圆柱试件环向形成压缩预应力,减弱了爆炸柱面波产生的环向拉伸破坏,破碎区半径、裂纹数目和裂纹几何尺寸随着围压的增大显著减小;距离炮孔越远,爆炸应力波强度降低、围压对裂纹的止裂作用逐渐增强。结合弹性力学和柱面弹性波理论对动静加载下应力场的变化进行分析发现,围压产生的环向压缩应力减小了爆炸形成的拉伸破坏,这一结论与实验结果相同。数值模拟结果表明：von Mises应力场随围压的升高而增强,而环向拉伸破坏随围压的升高而减弱,不同围压下的破碎半径和裂纹形态与实验结果基本一致。     

Boosting the Charge Transport Property of Indeno[1,2‐b]fluorene‐6,12‐dione though Incorporation of Sulfur‐ or Nitrogen‐Linked Side Chains

Alkyl chains are basic units in the design of organic semiconductors for purposes of enhancing solubility, tuning electronic energy levels, and tailoring molecular packing. This work demonstrates that the carrier mobilities of indeno[1,2‐b ]fluorene‐6,12‐dione ( IFD )‐based semiconductors can be dramatically enhanced by the incorporation of sulfur‐ or nitrogen‐linked side chains. Three IFD derivatives possessing butyl, butylthio, and dibutylamino substituents are synthesized, and their organic field‐effect transistors (OFET) are fabricated and characterized. The IFD possessing butyl substituents exhibits a very poor charge transport property with mobility lower than 10^?7 cm² V^?1 s^?1. In contrast, the hole mobility is dramatically increased to 1.03 cm² V^?1 s^?1 by replacing the butyl units with dibutylamino groups ( DBA‐IFD ), while the butylthio‐modified IFD ( BT‐IFD ) derivative exhibits a high and balanced ambipolar charge transport property with the maximum hole and electron mobilities up to 0.71 and 0.65 cm² V^?1 s^?1, respectively. Moreover, the complementary metal–oxide–semiconductor‐like inverters incorporated with the ambipolar OFETs shows sharp inversions with a maximum gain value up to 173. This work reveals that modification of the aromatic core with heteroatom‐linked side chains, such as alkylthio or dialkylamino, can be an efficient strategy for the design of high‐performance organic semiconductors.     

Fluorobenzotriazole (FTAZ)‐Based Polymer Donor Enables Organic Solar Cells Exceeding 12% Efficiency

The fluorobenzotriazole (FTAZ)‐based copolymer donors are promising candidates for nonfullerene polymer solar cells (PSCs), but suffer from relatively low photovoltaic performance due to their unsuitable energy levels and unfavorable morphology. Herein, three polymer donors, L24 , L68 , and L810 , based on a chlorinated‐thienyl benzodithiophene (BDT‐2Cl) unit and FTAZ with different branched alkyl side chain, are synthesized. Incorporation of a chlorine (Cl) atom into the BDT unit is found to distinctly optimize the molecular planarity, energy levels, and improve the polymerization activity. Impressively, subtle side chain length of FTAZ realizes a dramatic improvement in all the device parameters, as revealed by the short‐current density (J_sc) improved from 7.41 to 20.76 mA cm^?2, fill‐factor from 36.3 to 73.5%, and even the open‐circuit voltage (V_oc) from 0.495 to 0.790 V. The best power conversion efficiency (PCE) of 12.1% is obtained from the L810‐based device, which is one of the highest values reported for FTAZ‐based PSCs so far. Notably, the corresponding external quantum efficiency curve keeps a very prominent value up to 80% from 500 to 800 nm. The notable performance is discovered from the reduced energy loss, improved molecular face‐on orientation, the down‐shifted energy levels, and optimized absorption coefficient regulated by side‐chain engineering.