锡基钙钛矿太阳电池光吸收材料

钙钛矿太阳电池以其优异的光吸收特性、载流子传输能力以及简单的制备工艺,成为太阳电池领域研究的热点。高效、无污染、低成本一直是太阳电池领域追求的目标。然而,传统钙钛矿太阳电池由于其光吸收材料中含重金属元素铅,对环境有较大影响,从而限制了此类钙钛矿太阳电池的进一步商业化应用。基于此,科学家们都在致力于寻找新的无铅钙钛矿材料。在众多无铅钙钛矿材料中,锡基钙钛矿材料由于其相对较小的毒性、合适的带隙以及相应器件具有较高的能量转换效率等优点,成为最有希望应用于钙钛矿太阳电池的替代材料。然而,锡基钙钛矿太阳电池也存在一些弱点,其能量转换效率和器件稳定性相较于铅基钙钛矿太阳电池仍然存在很大差距,器件制备过程中对空气十分敏感。为了更好地解决这些问题,对锡基钙钛矿材料及器件性能的各种影响因素进行系统地研究势在必行。文章分类介绍了各类锡基钙钛矿材料及其在太阳电池中的应用,包括有机-无机杂化锡基钙钛矿材料,锡铅混合钙钛矿材料和全无机锡基钙钛矿材料,综述了锡基钙钛矿材料及其相应器件性能的最新研究进展,并且讨论了影响器件性能的各项因素,最后对锡基钙钛矿太阳电池未来的发展做出了展望。     

Sn类钙钛矿太阳电池薄膜的掺杂改性研究

采用一步法分别制备了Sn类CH3NH3Sn I3和Pb类CH3NH3Pb I3钙钛矿太阳电池薄膜材料,并对其表面形貌、微观结构、吸收光谱和电池器件性能进行了表征和测试。研究结果表明:Sn类钙钛矿材料的吸收光谱相对于Pb类钙钛矿材料发生了明显的红移,吸收截止波长从800 nm上升到950 nm左右,光学带隙由1.45 e V降低至1.21 e V左右;Sn类钙钛矿材料的光谱吸收范围明显扩大,但吸收强度有所降低,相应太阳电池器件的光电转换效率也明显低于Pb类钙钛矿太阳电池,分别为2.05%和6.71%。而Br的掺杂可使Sn类钙钛矿材料带隙变宽,吸收光子能量增大,电池器件的开路电压也相应提高。当Br含量由0增加至完全替代I时,Sn类钙钛矿材料逐渐由黑褐色转变为黄色,光学带隙增大至1.95 e V,但吸收截止波长由950 nm降低至650nm。值得提及的是当Br含量为0.5时,电池器件的光电转换效率可由最初的2.05%提升至2.94%。     

钙钛矿型太阳电池研究进展

自从2009年钙钛矿材料被应用到太阳电池领域,到现在仅6年的时间里,钙钛矿型太阳电池的光伏转换效率从约3%提高到20.1%,受到全球瞩目。 本文对近年来钙钛矿型太阳电池的发展进行了综述,介绍了钙钛矿吸光材料的性能及其制备,总结了钙钛矿型太阳电池器件结构及其内在机理,探讨了该类型电池待突破的方向和可能的解决途径,阐述了钙钛矿型太阳电池的进展历程,展望了未来发展方向。     

甲胺气体处理修复钙钛矿薄膜缺陷

正有机无机杂化钙钛矿由于其独特的光、电、磁性能以及制备工艺简单、成本低等特点,一直备受关注,特别是自2009年第一次将其应用于太阳能电池以来,钙钛矿太阳能电池的能量转换效率由3.8%迅速上升到目前的20.1%[1],并且钙钛矿在二极管和激光器件等领域也受到了广泛关注.在这些器件中,钙钛矿活性材料是其核心部分,钙钛矿膜的好坏是影响器件性能的关键因素,因此,对钙钛矿成膜性的研究具有     

有机及有机无机杂化太阳电池中的界面研究

第3代可溶液加工的太阳电池(包括有机太阳电池、钙钛矿太阳电池等),因为制备成本低、可制备柔性器件等特点备受关注.它们的迅速发展与活性层材料、界面材料与修饰以及器件工程等方面的快速发展息息相关,其中器件中的各个界面对激子的分离、载流子传递和收集有着巨大的影响,影响着器件的性能.本文重点介绍了近年来我们课题组在有机太阳电池、聚合物/量子点杂化太阳电池以及钙钛矿太阳电池研究中,如何设计界面材料以及通过自组装层对电极进行界面修饰,实现活性层和电极之间的欧姆接触和载流子的有效收集;如何在界面层中引入具有等离激元效应的纳米粒子实现光场的有效利用和性能的提升;以及如何对聚合物和纳米粒子间的界面修饰实现载流子的高效分离,制备高性能的杂化太阳电池器件.     

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.     

用CdSe/ZnS量子点提高体异质结有机太阳电池的效率

通过掺杂吸收光谱在可见光波段的量子点可提高聚合物对可见光的吸收,因此掺杂CdSe/ZnS核-壳结构量子点(CQDs)能提高聚(3-己基噻吩):[6,6]-苯基-C61-丁酸甲酯(P3HT:PCBM)体异质结太阳电池的能量转换效率.本文研究了CdSe/ZnS量子点在P3HT:PCBM中的不同掺杂比例及其表面配体对太阳电池光伏性能的影响,优化器件ITO(氧化铟锡)/PEDOT:PSS(聚(3,4-乙撑二氧噻吩:聚苯乙烯磺酸)/P3HT:PCBM:(CdSe/ZnS)/Al的能量转换效率达到了3.99%,与相同条件下没有掺杂量子点的参考器件ITO/PEDOT:PSS/P3HT:PCBM/Al相比,其能量转换效率提高了45.1%.     

卤原子取代苯并噻二唑聚合物给体材料的合成及其光伏性能研究

通过对苯并噻二唑单元进行氟、氯等卤原子取代,并同时调节烷基侧链的长度,设计合成了一系列基于苯并噻二唑四噻吩类的聚合物太阳电池材料.不同卤原子取代以及烷基侧链的长度都会影响聚合物的结晶性和薄膜聚集形貌从而改变其带隙和电荷传输性质.氟、氯原子的引入可调节聚合物的能级结构,而且相对于氟原子而言,具有更大原子半径的氯原子的引入可在更大尺度下调节能级结构,从而大幅提高相应太阳电池的开路电压,同时通过侧链的优化可进一步调节聚合物的微观聚集结构,改善器件能量转换效率.结果表明,在氯原子和氟原子共同作用的情况下,引入较长的侧链有利于提升聚合物的开路电压和短路电流,从而获得较好的器件性能.其中,以氯、氟共同取代的聚合物PCFBT4T-2OD与PC_(71)BM为活性层的器件性能最佳,能量转换效率可达8.84%.     

有机-无机杂化钙钛矿太阳电池中的钙钛矿层功能添加剂

有机-无机杂化钙钛矿太阳电池作为新一代薄膜太阳电池,自2009年Mayasaka等制备出第一块钙钛矿太阳电池后得到迅猛发展,截止目前,其认证转换效率由最初的3%达到22.1%。钙钛矿材料作为光吸收层,具有光吸收效率高、载流子迁移率高和电子扩散寿命长等特点,但是其本身对水和氧气敏感,在环境氛围中不稳定。研究表明,在钙钛矿材料中添加一些功能添加剂,通过调节钙钛矿晶体结构、结晶过程和晶体缺陷等方法,可以提高钙钛矿太阳电池的光伏性能或者环境稳定性。本文主要评述了钙钛矿太阳电池中各类功能添加剂的应用研究进展。     

钙钛矿太阳电池吸光层材料研究进展

近年来,有机-无机卤化铅钙钛矿太阳电池的研究取得了突破性进展,公证记录电池效率22.1%,与CdTe薄膜电池（认证记录电池效率22.1%）和CuInGaSn（CIGS）（认证记录电池效率22.3%）薄膜电池技术相媲美,已经接近于市场上主导地位的晶体硅太阳电池（约25%）。有机卤化铅钙钛矿太阳电池器件的长期效率输出稳定性和含毒性Pb严重制约其实际应用。本文将讨论有机卤化铅钙钛矿太阳电池不稳定性因素和相应的解决方案,并对钙钛矿材料中Pb元素的取代工作和无机非铅钙钛矿材料及其太阳电池的研究进行了阐述与展望。     

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 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.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.     

Exploring the scope of the Gewald reaction: Expansion to a four-component process

An efficient four-component reaction was developed to take advantage of the reactivity of the 2-aminothiophene-3-carbonitrile functionality, which is obtained during the classical three-component Gewald reaction. Various α-methylene bearing ketones were reacted with malononitrile, elemental sulfur, and aryl/heteroarylnitrile derivatives in t-BuOH/NaOH to afford 2-arylthieno[2,3-d]pyrimidin-4-amines in high yields. Preliminary studies revealed the photophysical properties of the products and their potential for use as metal sensors.