全固态介观太阳能电池:从染料敏化到钙钛矿

介观太阳能电池(Mesoscopic Solar Cells)作为新一代太阳能电池的突出代表,具有原材料来源丰富,制备工艺简单,光电转换效率高等优点,从而具有广阔的应用前景.本工作简要评述了全固态介观太阳能电池从染料敏化太阳能电池(Dye-sensitized solar cells)发展到钙钛矿太阳能电池(Perovskite solar cells)过程中新材料、新技术和新概念的研究进展.1998年,Gr?tzel课题组首次将固态有机空穴传输材料spiro-OMeTAD应用到染料敏化太阳能电池中,制备出全固态染料敏化太阳能电池,虽然仅获得了0.74%的光电转换效率,但是却使得全固态染料敏化太阳能电池迅速发展成为介观太阳能电池的重要研究方向.2012年,Park与Gr?tzel课题组合作,使用钙钛矿型吸光材料(CH3NH3)PbI3作为敏化剂,spiro-OMeTAD作为空穴收集层,制备出光电转换效率达到9.7%的全固态介观太阳能电池,又被称为钙钛矿太阳能电池.自此,基于钙钛矿材料的介观太阳能电池迅速成为太阳能电池领域的研究热点.目前,钙钛矿太阳能电池的最高公证效率已经达到20.1%.钙钛矿太阳能电池作为介观太阳能电池商业化道路上里程碑式的突破,在材料开发、界面优化以及器件稳定性方面的研究仍充满挑战,也期待新的突破.     

反式钙钛矿太阳能电池研究进展

反式结构的钙钛矿太阳能电池由于其稳定性好、迟滞效应低等优点越来越受到人们的关注. 自2013年出现以来, 其光电转换效率从最初3.9%快速提升至21.5%. 然而, 反式钙钛矿太阳能电池的光电转化效率相比于传统正置结构钙钛矿太阳能电池依然存在差距, 同时其柔性及空气稳定性和大面积制备技术的开发仍是当前急需亟待解决的难题. 本文就反式钙钛矿太阳能电池载流子传输材料的选择、界面优化及柔性器件的发展等方面进行了系统的综述, 试图总结由结构和材料优化实现反式钙钛矿太阳能电池的高效率、高稳定性、大面积及柔性制备的普遍规律.     

反式p-i-n结构钙钛矿太阳能电池

近年来,有机无机杂化金属卤化物钙钛矿太阳能电池的光电转换效率从最初3.8%提升到现在的21.0%.快速的效率提升主要得益于钙钛矿材料本身的光电特性—适宜的直隙半导体禁带宽度、较低的激子束缚能、较高的摩尔消光系数、优良的载流子双极性扩散特性.然而,高效率钙钛矿太阳能电池的器件稳定性和迟滞效应现象仍未得到很好的改善,是当前急需要解决的挑战性难题.本文首先回顾了钙钛矿太阳能电池的发展历程和器件结构的演变,结合本课题组在反式p-i-n结构钙钛矿太阳能电池方面的研究进展,试图阐明一些由电池结构带来的本质性差异和一些设计实现钙钛矿太阳能电池高效率、高稳定性、消除迟滞效应的普遍规律.着重总结了基于聚(3,4-亚乙二氧基噻吩)-聚(苯乙烯磺酸)(PEDOT:PSS)基与NiO基两类p型空穴传输材料的反式结构钙钛矿电池方面的代表性研究进展.     

少铅钙钛矿CH3NH3SrxPb(1-x)I3的合成及其在全固态薄膜太阳能电池中的应用

近年来,有机-无机杂化铅卤化物钙钛矿太阳能电池（PSCs）得到了迅猛发展,其最高光电转换效率已经达到19.3%.该类型太阳能电池使用的钙钛矿型吸光材料为含Pb的有机-无机杂化铅卤钙钛矿,从长远来看,Pb的毒性将制约其大规模应用.本文从减少吸光材料中Pb的含量出发,尝试用Sr部分取代Pb制备一系列少铅钙钛矿CH₃NH₃Sr_xPb_1-xI₃,并将其应用于钙钛矿太阳能电池进行光电性能的研究.研究结果表明,相比于全Pb钙钛矿（CH₃NH₃PbI₃）材料,Sr取代量为30%（x=0.3）时,所形成的CH₃NH₃Sr_0.3Pb_0.7I₃光谱吸收大范围增强,但基于此材料制备的电池器件性能明显下降.     

有机卤化铅钙钛矿太阳能电池

有机卤化铅钙钛矿太阳能电池因其低成本、高效率而受到了全世界的广泛关注。本文回顾了有机卤化铅钙钛矿太阳能电池的发展历史,介绍了有机卤化铅钙钛矿太阳能电池的研究进展,重点分析了有机卤化铅钙钛矿太阳能电池中有机卤化铅的组成,如一价阳离子A、二价阳离子B、卤素离子X的结构对光电性质的影响。对三种类型有机卤化铅钙钛矿太阳能电池即敏化类钙钛矿太阳能电池、介观超级结构钙钛矿太阳能电池、平面异质结钙钛矿太阳能电池的研究进展进行了评述,并指出有机卤化铅钙钛矿太阳能电池的研究趋势和今后的发展方向。     

环境友好型无铅卤化物钙钛矿太阳能电池研究进展

ABX_3(A为甲胺、甲脒等有机离子或铯离子,B为铅或锡等金属离子,X为溴、碘等卤化物离子)卤化物钙钛矿材料具有优异的光电特性,是当前太阳能电池研究的前沿和热点之一。然而,这类太阳能电池普遍面临含毒性元素铅和稳定性差等问题,极大地阻碍了钙钛矿太阳能电池商业化应用进程。因此,发展新型高效无铅钙钛矿太阳能电池势在必行。本文评述了环境友好型无铅卤化物钙钛矿太阳能电池的最新研究动态和进展,探讨了该类太阳能电池的制备、性能及其稳定性等问题,展望了其未来发展趋势。     

基于p型光电极的染料敏化太阳能电池研究进展

基于p型光电极的染料敏化太阳能电池是一种受到广泛关注的新型太阳能电池。根据电池的结构不同可以将其分为p型和p-n叠层型染料敏化太阳能电池。其中p-n型叠层染料敏化太阳能电池的理论光电效率可以达到43%,高于传统的基于n型TiO_2光阳极的染料敏化太阳能电池理论效率(30%),引起了科学界的高度关注。本文将总结基于p型光电极染料敏化太阳能电池(p型和p-n型叠层器件)的研究成果,重点介绍用于p型和p-n型叠层染料敏化太阳能电池的电极材料,染料及电解质的研究进展;同时总结目前该类电池发展中亟需解决的问题以及进一步提高器件效率的途径。     

卤化钙钛矿太阳能电池材料理论研究进展

卤化钙钛矿由于具有低成本、高效率等特点,最近作为非常有前景的太阳能电池吸收层材料被广泛研究。卤化钙钛矿型太阳能电池效率在短短的几年间由3.8%(2009年)迅速增加到22.1%(2016年)。卤化钙钛矿型太阳能电池的出现彻底改变了太阳能电池领域,不仅因为它们快速增长的效率,而且因为它们在材料生长和结构方面的可控性。卤化钙钛矿型太阳能电池的优越性能说明卤化钙钛矿材料具有独特的物理性质。在本综述中,我们总结了卤化钙钛矿材料最近几年在结构、电学、光学方面的理论研究成果,这些都与它们在太阳能电池方面的应用密切相关。我们也将探讨一些卤化钙钛矿型太阳能电池目前遇到的挑战以及可能的理论解决途径。     

基于p型光电极的染料敏化太阳能电池研究进展

基于p型光电极的染料敏化太阳能电池是一种受到广泛关注的新型太阳能电池。根据电池的结构不同可以将其分为p型和p-n叠层型染料敏化太阳能电池。其中p-n型叠层染料敏化太阳能电池的理论光电效率可以达到43%,高于传统的基于n型TiO₂光阳极的染料敏化太阳能电池理论效率（30%）,引起了科学界的高度关注。本文将总结基于p型光电极染料敏化太阳能电池（p型和p-n型叠层器件）的研究成果,重点介绍用于p型和p-n型叠层染料敏化太阳能电池的电极材料,染料及电解质的研究进展;同时总结目前该类电池发展中亟需解决的问题以及进一步提高器件效率的途径。     

钙钛矿材料组分调控策略及其光电器件性能研究进展

近年来，钙钛矿太阳电池的光电转换效率取得了爆发式增长，这与电池中钙钛矿薄膜的制备工艺和材料组分密切相关.关于钙钛矿薄膜的制备方法，相关的研究报道及综述较多，然而钙钛矿材料组分调控方面的研究梳理工作相对缺乏.本综述总结了近年来不同组分体系钙钛矿材料的研究进展，包括有机无机铅卤钙钛矿、全无机铅卤钙钛矿、少铅钙钛矿以及无铅钙钛矿.重点介绍了不同体系中具有代表性的材料组分及其对器件性能的影响，旨在梳理通过组分调控提高钙钛矿电池的效率及稳定性的研究思路，最终实现商业化应用.     

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%).     

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.     

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.     

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.     

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.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.