基于非卤素溶剂的高性能全聚合物太阳能电池

以聚合物PTB7-Th为给体、聚合物PDI-V为受体和四氢呋喃为溶剂,构筑了全聚合物太阳能电池.PTB7-Th与PDI-V光谱互补,有效地拓宽了活性层在可见光区的吸收范围,这有利于提高光电流.在器件优化过程中,发现热退火的方法可以有效地提高器件的光伏性能.尽管热退火处理对器件的开路电压影响不大,但是可以一定程度上提高器件的短路电流和填充因子,从而将电池的效率从7.1%提高到8.1%.8.1%的效率也是目前采用非卤素溶剂加工的基于苝酰亚胺类聚合物受体电池效率的最高值.该实验结果表明,四氢呋喃作为一种低毒性的有机非卤素溶剂,可以用来制备高性能有机光伏器件.     

倍增型有机光电探测器的研究进展

介绍了倍增型有机光电探测器的发展、工作机理、性能调控及相关的应用探索. 2015年张福俊课题组以单载流子传输通道的给受体混合(质量比约为100:1)薄膜为有源层，率先报道了界面附近受陷电子诱导空穴隧穿注入的倍增型有机光电探测器，并抑制了器件的暗电流密度.通过优化有源层厚度调控了界面附近受陷电荷的体分布，制备出超窄响应的倍增型有机光电探测器，并提出载流子注入窄化的新概念.利用三元策略及双层策略，制备出了宽响应倍增型有机光电探测器.利用光子俘获层调控器件的响应范围，以及利用倍增层获得了较大的外量子效率，将二极管型与倍增型器件的优势集中在一个器件中.引入光学调控层或将宽带隙材料引入有源层中，调控界面附近受陷电子分布，优化了器件的光谱形状，进而制备出响应光谱宽且平的倍增型有机光电探测器.将制备的倍增型有机光电探测器应用到心率监测、单像素成像及光开关等领域，取得较好的应用成果.     

基于窄带系DPP类聚合物的高性能近红外有机光探测器件

采用窄带隙给体材料DPPDTT和富勒烯衍生物受体PCBM共混作为活性层,制备了具有高激子分离和电荷传输效率的近红外有机光探测器件,并进一步采用窄带隙受体Y6代替PCBM制备一种"双窄带隙吸收"的异质结结构,在近红外区域的吸收叠加有效地增强了器件光响应能力.最后,通过采用厚活性层、插入阻挡层以及制备倒置结构等方法,将器件...     

倍增型有机光电探测器的研究进展

介绍了倍增型有机光电探测器的发展、工作机理、性能调控及相关的应用探索.2015年张福俊课题组以单载流子传输通道的给受体混合(质量比约为100∶1)薄膜为有源层,率先报道了界面附近受陷电子诱导空穴隧穿注入的倍增型有机光电探测器,并抑制了器件的暗电流密度.通过优化有源层厚度调控了界面附近受陷电荷的体分布,制备出超窄响应的倍...     

有机太阳能电池性能衰减机理研究进展

近年来随着非富勒烯Y系列明星分子受体的出现, 单结有机太阳能电池的光电转换效率已经突破19%, 但是器件在运行条件下缺乏良好的稳定性, 严重制约了其商业化发展. 因此越来越多的研究聚焦于造成有机太阳能电池性能衰减的原因以及如何提高有机太阳能电池的稳定性. 由于有机太阳能电池复杂的器件结构、不尽相同的活性层材料以及在稳定性研究中条件的差异, 造成了对有机太阳能电池器件衰减研究的困难. 为了更全面地了解有机太阳能电池的衰减过程, 对近些年有机太阳能电池器件衰减过程的研究成果进行综述, 总结了由于给受体材料化学分解、活性层形貌变化、传输层和电极腐蚀以及界面反应等原因造成的器件性能衰减, 并介绍了近些年关于提高器件稳定性的一些策略, 最后对有机太阳能电池的未来发展进行了展望.     

聚合物光伏材料与器件研究进展

高效率的聚合物太阳电池依赖于光吸收活性层材料对太阳光能量的充分利用．电极界面材料将光吸收活性层产生的空穴和电子分别快速高效地抽取到阳极和阴极,并通过进一步改进光伏器件的结构提升能量转换效率和稳定性．本课题组在光吸收活性层中新型聚合物给体材料、新型电极界面材料、利用水／醇性电极界面材料制作新型倒装器件结构的太阳电池方面取得重要进展,推动了太阳电池在能量转换效率和稳定性方面的突破．     

杂化太阳电池中异质结界面的修饰及其对电池光电性能的影响

有机-无机杂化太阳电池综合了有机、无机材料的优点,成本低、理论效率高,受到人们的广泛关注.杂化太阳电池的光活性层由无机半导体和有机共轭聚合物复合而成.当光照射到活性层上时,共轭聚合物吸收光子产生激子(电子-空穴对);激子迁移到有机给体-无机受体的异质结界面处发生解离而产生自由电子和空穴;自由电子和空穴分别向无机半导体和有机聚合物传输,从而实现电荷的分离和传导.激子在有机-无机异质结界面处的分离效率是影响电池性能的一个重要因素.有机、无机两相材料往往因为接触面积小以及相容性差使此两相材料接触不佳,激子迁移到此界面不能有效分离,从而严重影响了杂化太阳电池的效率.这个问题可以通过此界面的修饰加以改善.本文即综述了有机-无机异质结界面修饰的方法、作用和意义,并展望了杂化太阳电池未来的发展趋势和应用前景.     

半透明有机太阳能电池研究进展

半透明有机光伏(ST-OPVs)相比其它无机光伏技术,因为其活性层材料可调节的电子能级和选择性的吸收光谱,在作为温室的发电屋顶、现代建筑外墙和采光玻璃等应用中具有本征优势.随着高效窄带隙聚合物给体和近红外非富勒烯受体材料的快速发展, ST-OPVs的光利用效率在过去十年取得了显著进展,本征和具有光学修饰的半透明器件的光利用效率分别超过了3%和5%.为了进一步推动半透明有机光伏技术的实用化,进一步提升器件的光利用效率仍是研究重点.基于此，本文分别从半透明器件的理论模型、活性层材料设计和器件光学修饰等角度综合评述了近期ST-OPVs的重要进展,为未来器件性能的优化提供了参考.     

结晶动力学策略在非富勒烯体系太阳能电池形貌调控领域的应用

非富勒烯体系太阳能电池具有吸收范围宽、半透明及可大面积溶液加工等优势,已在清洁能源领域占据重要地位。在高性能材料开发、活性层形貌及器件工艺优化的推动下,器件能量转换效率已经突破19%。非富勒烯体系太阳能电池的基本结构包括阴极、阳极、相应的界面层及活性层,其中活性层形貌对器件性能有着重要影响。然而,由于活性层中给体与受体分子均为半晶性分子,在成膜过程中两者结晶存在竞争耦合;此外,活性层的结晶和相分离往往同时发生,导致形貌可控性差。针对上述问题,本专论系统总结了通过控制共混体系结晶动力学,精细调控活性层形貌的相关进展,详细介绍了共混体系中分子扩散速率、成核与晶粒生长相对速率、结晶顺序等动力学行为对活性层相分离结构、相区尺寸、结晶度及分子取向等的影响,建立了活性层多层次结构与器件光物理过程间的构效关系,为制备高性能有机太阳能电池器件奠定了基础。     

利用扫描开尔文探针显微镜观察薄膜光电器件能级排布

薄膜光电器件的能级结构直接决定了载流子的产生、分离、传输、复合和收集等微观动力学过程,从而决定了器件性能。因此准确获取器件能级结构,是深入理解器件工作机制、推动器件技术革新的重要科学依据。此专论系统地介绍了本课题组利用扫描开尔文探针显微镜(SKPM)表征薄膜光电器件如有机太阳能电池、有机-无机钙钛矿光探测器等器件中界面能级结构的工作。垂直型薄膜器件中的活性材料层被顶电极与底电极封闭,通常难以直接在器件工况下测量其中的界面能级排布,我们发展了横截面SKPM技术来解决这一难题。研究表明,界面层是调控器件能级结构、决定器件极性、提高器件性能的重要手段。本文介绍的表征技术有望在各种薄膜光电器件,诸如光伏器件、光探测器、发光二极管,尤其是各种叠层构型器件的研究中展现出广阔的应用前景。     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.