Improving the performance of polymer solar cells by altering polymer side chains and optimizing film morphologies

Two donor–acceptor (D–A) type conjugated polymers using dodecyl- and ethylhexyl-thiophene substituted benzo[1,2-b:4,5-b′]dithiophene (BDT-DDT and BDT-EHT, respectively) as donors and n-alkylthieno[3,4-c]pyrrole-4,6-dione (TPD) as acceptor were synthesized and characterized. The thiophene substituted BDT unit was recognized as a two-dimensional (2D) π-extended segment with high carrier mobility and TPD unit was a relatively strong electron-drawing acceptor, which could lead to deep-lying highest occupied molecular orbital (HOMO) levels of the polymers. The optical properties, electrochemical behavior, and charge carrier properties of the polymers were compared in parallel. The results indicated that ethylhexyl-substitution could optimize the polymer structures and properties. The bulk-heterojunction polymer solar cells (PSCs) based on the two polymers were fabricated and characterized. The devices based on ethylhexyl-substituted polymer showed better performance than that of dodecyl-substituted one. Further analysis proved that the improvement was mainly ascribed to the formation of well-defined nanostructures by using branched ethylhexyl side chains, which facilitated charge separation and transport in the bicontinous active layer. This study suggests that obtaining appropriate film morphology and phase separation by altering alkyl side chains is extraordinary important for high performance PSCs based on D–A type polymers.     

基于LVF的光谱测量系统

为了实时、快捷、无损获取作物生长信息,采用新型的线性可调谐滤光片(LVF)分光技术,研制了作物生长信息光谱测量系统.选取线性可调谐滤光片为分光单元,硬件系统单元采用线阵CMOS探测器,在驱动单元脉冲信号的作用下完成光电转换、存储和转移等功能,并采用USB数据采集板对光电信号进行AD转换.上位机界面采用MFC和OpenGL语言编程.在室内用卤钨灯光源对玉米叶片进行验证,试验表明该系统能够较好地实现玉米冠层反射光谱的实时检测,在玉米叶绿素快速诊断方面具有可行性,为作物生长监测设备的研发提供了有力支持.     

基于无线射频的公交预报站系统

公交预报站系统是城市智能交通系统的重要组成部分,可以有效地优化公交调度、提高市民乘车效率。本文设计了基于无线射频技术和STC12C5A单片机的公交预报站系统,可以代替常用的基于GPS技术的公交预报站系统。系统通过无线射频技术,以接力方式将公交到站信息传输到下行站点,并在站点通过语音和LED显示两种方式对即将到站的公交车信息进行预报,方便市民选择合适的公交乘车方式。本文主要介绍了系统的组成和硬件设计。     

制冷型红外焦平面探测器引线键合质量优化研究

介绍了制冷型红外焦平面探测器引线键合工艺,分析和总结了焦平面探测器引线键合的失效模式,对主要失效模式进行了优化研究和试验验证,提出了引线键合的质量控制方法,并给出了相应的测试结果,对提高焦平面探测器引线键合具有很好的指导意义.     

高校普通学生棒垒球运动的实践探索

本文通过实践总结法、文献资料法、专家访谈法、学生问卷调查法对高校开设棒垒球的情况进行总结,并通过江苏省十七届运动会的慢投垒球第一次比赛,发现高校对此项运动颇感兴趣并投入很多;南京理工大学六年来的开课经验表明,高校应该尽快开设此课,并对开课所要注意的事项和必须的改变进行陈述,以供其他学校借鉴交流;指出课内外相结合是今后学校体育的发展方向。     

十字差动式小视场超高精度太阳敏感器

设计了一种专门用于对日观测成 像稳像系统的超高精度太阳敏感器。针对传统的四象限 太阳敏感器的不足,设计了一种基于十字差动式太阳硅光电池片 的探测器,以提高灵敏度和抗干扰能力。该系统在有效视场 (1°)内具有10''的低误差。     

电子束诱导沉积钴微米线及其铁磁性

通过电子束诱导沉积的方法制备了钴(Co)微米线,并利用扫描电子显微镜(SEM)、原子力/磁力显微镜(AFM/MFM)以及物性测量系统(PPMS)等手段对Co微米线的沉积尺寸、微结构、铁磁性和电学性质进行了测试和分析。研究结果表明:Co微米线轮廓清晰、均匀性好。在不同的沉积条件下,微米线的实际长度与设定长度基本一致;实际宽度数据呈类梯形分布,半高宽是设定值的2~10倍;实际厚度低于设定厚度的60%。沉积电流对Co微米线的铁磁特性有重要影响。当沉积电流大于0.5 nA时,样品呈现出良好的铁磁特性。另外,电学性能测试结果显示Co微米线呈现绝缘特性。成功制备了室温铁磁绝缘Co微米线,这将有助于深入开展微纳尺度的结构与器件的研究和应用。     

探究讨论式教学法在"数字电路"中的应用

探究讨论式教学法是一种通过探索、研究和讨论培养学生质疑精神、创新意识和创新能力的教学方法.本文给出了探究讨论式教学法的架构,分别从理论教学和实践教学两方面详细阐述了探究讨论式教学法在"数字电路"课程中的应用.同时给出了该教学方法下的课程考核模式及教学效果.总结了在教学过程中遇到的问题和困难.     

Selective Pd Deposition on Au Nanobipyramids and Pd Site‐Dependent Plasmonic Photocatalytic Activity

The synthesis of anisotropic metal nanostructures is strongly desired for exploring plasmon‐enabled applications. Herein, the preparation of anisotropic Au/SiO₂ and Au/SiO₂/Pd nanostructures is realized through selective silica coating on Au nanobipyramids. For silica coating at the ends of Au nanobipyramids, the amount of coated silica and the overall shape of the coated nanostructures exhibit a bell‐shaped dependence on the cationic surfactant concentration. For both end and side silica coating on Au nanobipyramids, the size of the silica component can be varied by changing the silica precursor amount. Silica can also be selectively deposited on the corners or facets of Au nanocubes, suggesting the generality of this method. The blockage of the predeposited silica component on Au nanobipyramids enables further selective Pd deposition. Suzuki coupling reactions carried out with the different bimetallic nanostructures functioning as plasmonic photocatalysts indicate that the plasmonic photocatalytic activity is dependent on the site of Pd nanoparticles on Au nanobipyramids. Taken together, these results suggest that plasmonic hot spots play an important role in hot‐electron‐driven plasmonic photocatalysis. This study opens up a promising route to the construction of anisotropic bimetallic nanostructures as well as to the design of bimetallic plasmonic‐catalytic nanostructures as efficient plasmonic photocatalysts.     

Light‐Fueled,Spatiotemporal Modulation of Mechanical Properties and Rapid Self‐Healing of Graphene‐Doped Supramolecular Elastomers

Gaining spatially resolved control over the mechanical properties of materials in a remote, programmable, and fast‐responding way is a great challenge toward the design of adaptive structural and functional materials. Reversible, temperature‐sensitive systems, such as polymers equipped with supramolecular units, are a good model system to gain detailed information and target large‐scale property changes by exploiting reversible crosslinking scenarios. Here, it is demonstrated that coassembled elastomers based on polyglycidols functionalized with complementary cyanuric acid and diaminotriazine hydrogen bonding couples can be remotely modulated in their mechanical properties by spatially confined laser irradiation after hybridization with small amounts of thermally reduced graphene oxide (TRGO). The TRGO provides an excellent photothermal effect, leads to light‐adaptive steady‐state temperatures, and allows local breakage/de‐crosslinking of the hydrogen bonds. This enables fast self‐healing and spatiotemporal modulation of mechanical properties, as demonstrated by digital image correlation. This study opens pathways toward light‐fueled and light‐adaptive graphene‐based nanocomposites employing molecularly controlled thermal switches.