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单结太阳电池的能量转换效率从根本上受限于Shockley-Queisser(S-Q)理论极限,二端叠层结构可同时解决单结器件中面临的光谱失配和热弛豫能量损耗问题,是突破S-Q极限最有前途的实用技术。二端叠层太阳电池中的复合层作为中间层的重要组分,为来自两侧的电子和空穴提供复合位点,避免了电荷堆积造成的开路电压损失并促进了电流流通,是实现高性能叠层器件的关键因素之一。理想的复合层应具有较高电导率以提高电荷复合速率、高光学透过率以保证后结子电池的有效光吸收、良好的化学稳定性以降低溶剂对子电池的溶解伤害以及较低的制备成本以推动叠层电池的商业化生产进程。目前已有多种材料被应用于二端叠层太阳电池中,如薄金属、透明导电氧化物、导电聚合物、氧化石墨烯等,在钙钛矿-钙钛矿、钙钛矿-有机、钙钛矿-晶硅叠层器件中发挥了重要作用。本文归纳了不同类型叠层太阳电池复合层的研究进展,系统介绍了复合层的种类、设计原则、制备工艺等,对比其优缺点并提出了复合层目前存在的问题和面临的挑战,为制备高效叠层电池提供了有益参考。 相似文献
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自2009年第一次报道以来,有机-无机杂化钙钛矿太阳电池(PSCs)的光电转换效率(PCE)从3.8%提升至25.5%,已可以与商业化的晶体硅太阳电池相媲美,引起全世界研究者的极大关注.然而,由于杂化物晶体结构中有机成分弱的化学键,器件长期稳定性受到很大的影响.近年来,用无机Cs+完全取代有机基团构成全无机卤化物钙钛矿被认为是解决太阳电池稳定性问题的有效途径.在Cs基钙钛矿之中,CsPbBr3具有最优异的耐热、耐光、耐湿性能,作为顶电池具有与晶体硅太阳电池组成长寿命叠层太阳电池的潜力.本文系统地综述了CsPbBr3 PSCs领域的研究进展,首先介绍了CsPbBr3 PSCs的发展历史及CsPbBr3的晶体结构和基本特性,随后阐述了CsPbBr3薄膜的制备方法、CsPbBr3的元素掺杂改性、器件的界面工程等方面的研究进展;最后,讨论了当前存在的问题和提高CsPbBr3 PSCs性能的未来方向,为进一步推动钙钛矿太阳电池的实用化进程提供参考. 相似文献
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以钙钛矿电池为顶电池的叠层太阳电池发展迅速,成为太阳能光伏领域的研究热点之一。随着电池结构和制备工艺的优化,叠层电池的光电转换效率快速提升,单片钙钛矿/晶硅叠层电池的效率已达到31.3%。本综述对近年来以宽带隙钙钛矿电池作为顶子电池、晶体硅电池及其他新型中窄带隙电池(钙钛矿电池、有机电池、铜铟镓硒(CIGS)电池)作为底子电池的叠层电池的研究进展进行了系统梳理,总结了叠层电池的顶电池、中间互联层和底电池的材料、结构及光电性能等方面的关键技术及难点,希望能够为进一步提升叠层电池效率提供一些思路。并对未来低成本高效叠层太阳能电池的光学和电学优化需求做出了分析与展望。 相似文献
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近几年来, 钙钛矿电池发展迅速, 其单电池效率从最初的3.8%迅速提升至目前20.1%, 接近硅基太阳能电池的光电转换效率。TiO2、ZnO、Al2O3等诸多无机纳米金属氧化物材料作为重要的载流子输运材料与钙钛矿生长骨架也被广泛地应用于钙钛矿电池。依据钙钛矿电池功能结构的差异, 本文分别介绍了此类材料作为钙钛矿电池中的致密层及介孔层的制备方法, 并在此基础上介绍了基于表面修饰、掺杂、复合等氧化物的改性手段调节材料理化性能与氧化物/钙钛矿界面特性, 进而改进钙钛矿电池性能的方法。并阐述了进一步提高钙钛矿电池光电转换效率需要关注的重点问题及展望。 相似文献
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使用有机无机杂化钙钛矿材料作为光吸收层的钙钛矿太阳能电池自进入人们的视野以来,其制备工艺和器件结构不断得到优化,短短几年内效率取得了非常可观的增长。与此同时,这种基于三维钙钛矿材料的电池的缺点也越来越突出,尤其是材料的不稳定性,严重阻碍了其发展。低维钙钛矿材料具有有机胺层与无机层(金属卤化物钙钛矿晶体)之间相互交替的低维(层状)结构,其中被有机胺隔开的独立钙钛矿层中八面体的层数n越小,钙钛矿越接近二维结构。相比传统三维钙钛矿结构,低维钙钛矿材料应用于光伏器件具有两大优势:(1)耐湿性、光热稳定性大大增强;(2)可以通过改变n和插入的有机胺的种类来实现光学及电学性质的可调性。然而,低维钙钛矿具有较大的光学带隙,有机胺的引入降低了载流子迁移率,导致低维钙钛矿电池的效率明显低于三维钙钛矿电池。因此,近三年来除研究钙钛矿层数对材料性质和器件性能的影响外,研究者们主要从选择合适的有机胺和优化薄膜制备工艺方面不断尝试,并取得了丰硕的成果,在充分发挥低维钙钛矿稳定性优势的同时大幅提升了器件效率。目前,低维钙钛矿太阳能电池的光电转换效率已由2014年的4.37%跃升至13.7%。在较高效率的低维钙钛矿太阳能电池中已取得成功应用的有机胺类包括苯乙胺(PEA)、正丁胺(n-BA)、异丁胺(iso-BA)、聚乙烯亚胺(PEI)等。其中PEA应用得最早;n-BA是运用在目前为止最高效的低维钙钛矿电池中的有机胺;而PEI插层形成的低维钙钛矿拥有相对更小的光学带隙和更高的耐湿性,但载流子的传输会受到更大的限制。低维钙钛矿薄膜的制备起初主要采用简单的一步旋涂法,但此法所得的低维钙钛矿平行于基底生长,器件效率很低。近两年的研究工作将基底预热、浸泡、反溶剂滴加等手段引入到钙钛矿旋涂工艺中,实现了低维钙钛矿优先垂直基底生长,为突破低效率瓶颈提供了可能。此外,以三维钙钛矿为基础,以有机胺为添加剂,制得的二维和三维混合的钙钛矿结构,也可以实现器件效率和稳定性的双提升。本文归纳了低维钙钛矿光伏器件的研究进展,分别对低维钙钛矿的分子结构、插入的有机胺的选择、钙钛矿薄膜的制备方法等进行介绍,分析了低维钙钛矿太阳能电池面临的问题并展望其前景,以期为制备稳定和环境友好的新型钙钛矿太阳能电池提供参考。 相似文献
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有机无机杂化钙钛矿材料具有优异的光电特性,在光伏、显示和传感领域均获得了广泛关注。近年来,钙钛矿太阳能电池技术发展迅速,在效率提升和面积放大方面不断取得突破,但钙钛矿材料和器件的稳定性问题一直没能得到根本性的解决,严重制约了钙钛矿光伏器件的实用性能及商业化推广进程。钙钛矿太阳能电池的不稳定性来源于器件中钙钛矿层、电荷传输材料和电极材料的失效,失效原因主要包括光照、水分、温度和氧气等环境因素,因此深入理解各因素对钙钛矿太阳能电池稳定性的作用机理至关重要。此外,与晶硅和其他薄膜电池相比,钙钛矿太阳能电池在材料性能、器件结构等方面都有较大差别。目前晶硅电池和其他薄膜电池的稳定性评价方法和测试手段对钙钛矿太阳能电池不能完全适用,为了使不同机构间钙钛矿太阳能电池稳定性的测试结果可以对比,需要统一稳定性测试标准。本文总结了钙钛矿材料及光伏器件稳定性的影响因素,剖析了光照、水分、温度和氧气等环境因素对钙钛矿器件稳定性的作用机理,并对提升钙钛矿太阳能电池稳定性的方法进行了综述。最后分析了钙钛矿太阳能电池稳定性的评价方法和测试手段,并对钙钛矿太阳能电池的未来发展方向进行了预测,以期为钙钛矿太阳能电池商业... 相似文献
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新型太阳能电池包括有机太阳能电池、钙钛矿太阳能电池和量子点太阳能电池等,是一类十分有前景的光伏器件,目前有机太阳能电池和钙钛矿太阳能电池的能量转换效率分别超过了19%和25.6%。富勒烯材料具有较高的电子迁移率和良好的电子特性,被广泛应用于有机太阳能电池活性层、界面层,钙钛矿太阳能电池活性层和中间层等。在有机太阳能电池中,富勒烯材料作为活性层受体,可以提高器件电子传输能力;作为界面修饰层,可以有效降低接触电阻,抑制载流子的复合。在钙钛矿太阳能电池中,富勒烯材料作为活性层添加剂能钝化钙钛矿缺陷,抑制迟滞效应;作为中间层能优化界面形貌,促进电荷的提取与输运。本文综述了富勒烯材料在各个组成部分中的研究进展,并展望了富勒烯材料在各个组成部分中的发展前景,在此基础上,提出了未来的研究方向。 相似文献
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Alinaghi Salari Sila Appak‐Baskoy Maya Ezzo Boris Hinz Michael C. Kolios Scott S. H. Tsai 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(9)
The interaction of a sound or ultrasound wave with an elastic object, such as a microbubble, can give rise to a steady‐state microstreaming flow in its surrounding liquid. Many microfluidic strategies for cell and particle manipulation, and analyte mixing, are based on this type of flow. In addition, there are reports that acoustic streaming can be generated in biological systems, for instance, in a mammalian inner ear. Here, new observations are reported that individual cells are able to induce microstreaming flow, when they are excited by controlled acoustic waves in vitro. Single adherent cells are exposed to an acoustic field inside a microfluidic device. The cell‐induced microstreaming is then investigated by monitoring flow tracers around the cell, while the structure and extracellular environment of the cell are altered using different chemicals. The observations suggest that the maximum streaming flow induced by an MDA‐MB‐231 breast cancer cell can reach velocities on the order of mm s?1, and this maximum velocity is primarily governed by the overall cell stiffness. Therefore, such cell‐induced microstreaming measurements, including flow pattern and velocity magnitude, may be used as label‐free proxies of cellular mechanical properties, such as stiffness. 相似文献
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A multivariate dataset consists of n cases in d dimensions, and is often stored in an n by d data matrix. It is well-known that real data may contain outliers. Depending on the situation, outliers may be (a) undesirable errors, which can adversely affect the data analysis, or (b) valuable nuggets of unexpected information. In statistics and data analysis, the word outlier usually refers to a row of the data matrix, and the methods to detect such outliers only work when at least half the rows are clean. But often many rows have a few contaminated cell values, which may not be visible by looking at each variable (column) separately. We propose the first method to detect deviating data cells in a multivariate sample which takes the correlations between the variables into account. It has no restriction on the number of clean rows, and can deal with high dimensions. Other advantages are that it provides predicted values of the outlying cells, while imputing missing values at the same time. We illustrate the method on several real datasets, where it uncovers more structure than found by purely columnwise methods or purely rowwise methods. The proposed method can help to diagnose why a certain row is outlying, for example, in process control. It also serves as an initial step for estimating multivariate location and scatter matrices. 相似文献
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Xuan Mu Wenfu Zheng Jiashu Sun Wei Zhang Xingyu Jiang 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(1):9-21
Microfluidics, a toolbox comprising methods for precise manipulation of fluids at small length scales (micrometers to millimeters), has become useful for manipulating cells. Its uses range from dynamic management of cellular interactions to high‐throughput screening of cells, and to precise analysis of chemical contents in single cells. Microfluidics demonstrates a completely new perspective and an excellent practical way to manipulate cells for solving various needs in biology and medicine. This review introduces and comments on recent achievements and challenges of using microfluidics to manipulate and analyze cells. It is believed that microfluidics will assume an even greater role in the mechanistic understanding of cell biology and, eventually, in clinical applications. 相似文献
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Donggyu Lee Daehee Lee Yulim Won Hyeonaug Hong Yongjae Kim Hyunwoo Song Jae‐Chul Pyun Yong Soo Cho Wonhyoung Ryu Jooho Moon 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(11):1446-1457
Effective insertion of vertically aligned nanowires (NWs) into cells is critical for bioelectrical and biochemical devices, biological delivery systems, and photosynthetic bioenergy harvesting. However, accurate insertion of NWs into living cells using scalable processes has not yet been achieved. Here, NWs are inserted into living Chlamydomonas reinhardtii cells (Chlamy cells) via inkjet printing of the Chlamy cells, representing a low‐cost and large‐scale method for inserting NWs into living cells. Jetting conditions and printable bioink composed of living Chlamy cells are optimized to achieve stable jetting and precise ink deposition of bioink for indentation of NWs into Chlamy cells. Fluorescence confocal microscopy is used to verify the viability of Chlamy cells after inkjet printing. Simple mechanical considerations of the cell membrane and droplet kinetics are developed to control the jetting force to allow penetration of the NWs into cells. The results suggest that inkjet printing is an effective, controllable tool for stable insertion of NWs into cells with economic and scale‐related advantages. 相似文献