柔性染料敏化太阳能电池和柔性钙钛矿太阳能电池关键电极材料研究进展

柔性太阳能电池具有轻便、可弯曲的优点,可用于可穿戴设备等器件的即时充电,具有广阔的应用前景,受到持续广泛的关注。柔性太阳能电池制备中的关键在于基材以及与之相关的电极材料的制备。本文综述了柔性染料敏化太阳能电池和柔性钙钛矿太阳能电池近几年的发展情况,着重介绍了柔性染料敏化太阳能电池光阳极、对电极以及柔性钙钛矿太阳能电池的底电极和电子传输层。结果发现高温烧结目前仍是制备高效染料敏化太阳能电池光阳极不可避免的方法,而对电极则不受这一限制并且已经有多种材料的效率超过了高温烧结的铂。柔性钙钛矿太阳能电池的研究重点是用其他材料代替底电极中柔性较差的ITO以及高温烧结的电子传输材料TiO₂,并且都取得显著成效。在此基础上,展望了柔性染料敏化太阳能电池和柔性钙钛矿太阳能电池未来的发展方向。     

碳材料在太阳能电池对电极中的研究进展

简要说明了太阳能电池对电极的作用,并阐述了铂对电极、镍对电极、聚合物对电极和氧化铜对电极目前的发展状况.碳材料具有良好的导电性能和催化性能,具有制备太阳能电池对电极的基本性质.详细论述了碳材料对电板的制备工艺及其性能参数,与其它对电极相比,碳材料制备的对电极导电性能好,光电转化率可达到铂电极的90%,优于其它材料制备的对电极,而且价格低廉,因此碳材料对电极具有广阔的发展前景.碳材料对电极是染料敏化太阳能电池的重要研究方向.     

Historical Analysis of High-Efficiency,Large-Area Solar Cells: Toward Upscaling of Perovskite Solar Cells

The status and problems of upscaling research on perovskite solar cells, which must be addressed for commercialization efforts to be successful, are investigated. An 804 cm² perovskite solar module has been reported with 17.9% efficiency, which is significantly lower than the champion perovskite solar cell efficiency of 25.2% reported for a 0.09 cm² aperture area. For the realization of upscaling high-quality perovskite solar cells, the upscaling and development history of conventional silicon, copper indium gallium sulfur/selenide and CdTe solar cells, which are already commercialized with modules of sizes up to ≈25 000 cm², are reviewed. GaAs, organic, dye-sensitized solar cells and perovskite/silicon tandem solar cells are also reviewed. The similarities of the operating mechanisms between the various solar cells and the origin of different development pathway are investigated, and the ideal upscaling direction of perovskite solar cells is subsequently proposed. It is believed that lessons learned from the historical analysis of various solar cells provide a fundamental diagnosis of relative and absolute development status of perovskite solar cells. The unique perspective proposed here can pave the way toward the upscaling of perovskite solar cells.     

染料敏化太阳能电池对电极的研究进展

综述了近年来染料敏化太阳能电池对电极的种类、特点及制作方法的研究进展情况,对不同种类对电极的制备方法及其优缺点进行了比较,指出了贵金属类对电极的不足,同时也给出了非金属类对电极的优势.最后提出,大力开展非金属类低价高效的对电极研究是今后染料敏化太阳能电池课题研究的一个重要方向,并对染料敏化太阳能电池的前景进行了展望.     

染料敏化太阳能电池的研究进展

综述了近年来关于染料敏化太阳能电池制备的研究状况,详细介绍了国内外关于二氧化钛薄膜、反电极、染料和电解质的设计思路及制备情况,并讨论了制备方法对太阳能电池性能的影响.     

钙钛矿太阳能电池技术发展历史与现状

简要回顾了钙钛矿太阳能电池的发展历史,解释了钙钛矿太阳能电池本质上是固态染料敏化太阳能电池。介绍了钙钛矿太阳能电池的微观发电机理,结合钙钛矿太阳能电池的能级图分析讨论了钙钛矿与电子传输层和空穴传输层的能级匹配。分析总结了钙钛矿太阳能电池的光伏技术参数,包括光生电流密度、开路电压、填充因子、能量转换效率以及光伏性能的稳定性。钙钛矿太阳能电池的能量转换效率、短路电流密度和开路电压均已超过非晶硅薄膜太阳能电池,填充因子与非晶硅薄膜太阳能电池很接近。钙钛矿太阳能电池有希望实现产业化而成为下一代薄膜太阳能电池。指出了钙钛矿太阳能电池大规模市场应用在制造技术上的瓶颈即空穴传输层的造价昂贵,并综述了解决该瓶颈的最新研究工作。     

原子层沉积技术在新型太阳能电池中的应用

原子层沉积技术(ALD)是一项正处于发展之中、在许多领域具有巨大应用前景的新型材料制备技术,该技术在纳米结构和纳米复合结构的制备方面显示出独特的优势,在新型薄膜太阳能电池领域呈现出巨大的发展潜力和前景。首先概述了ALD技术的工作原理,简要介绍了近几年ALD技术在硅基太阳能电池和铜铟镓硒薄膜电池(CIGS)中的应用,然后重点综述了原子层沉积纳米功能薄膜在染料敏化太阳能电池(DSSCs)和有机-无机杂化钙钛矿太阳能电池(PSCs)为代表的新型薄膜太阳能电池中的应用。最后,总结了原子层沉积功能薄膜的特点和优势,展望了ALD在新能源材料与器件领域的应用前景和发展趋势。     

离子液体在有机光电转换器件中的应用研究进展

近年来,离子液体因具有不易挥发、性质稳定、透光性好、导电率高、可设计性,以及易于在界面处形成双电层等物理化学性质,而展现出广阔的应用潜力和前景,逐渐成为国际科学研究的前沿和热点之一。其中,将离子液体应用于染料敏化太阳能电池(Dye-sensitized solar cells,DSSCs)、钙钛矿太阳能电池和有机光电探测器等有机光电转换器件的研究备受关注。 在有机光电转换器件中,离子液体在染料敏化太阳能电池方面的应用最为广泛且完善。高效DSSCs主要是基于有机溶剂的液态电解质结,但有机溶剂在带来较高光电转换效率的同时,其本身存在的易挥发汽化、光热稳定性差等缺点,导致DSSCs的器件寿命与长期稳定性受到影响,离子液体的引入能有效解决以上问题。此外,离子液体还以电子传输层以及界面修饰层的形式引入,具有高电荷迁移率、低功函数以及高稳定性等优点,能在一定程度上改善器件的短路电流、填充因子和光电转换效率等。因此,离子液体成为在DSSCs的实际应用中兼具性价比高、封装难度低、性能好、稳定性高四大优点的辅助材料。在钙钛矿太阳能电池方面,离子液体的低功函数和高电子迁移率以及一些特殊性质如钝化反应、黏度效应等,都能够实现对电子萃取率、电荷转移电阻、钙钛矿结晶情况等方面的控制以满足实际设计要求,进而有助于钙钛矿太阳能电池的光电转换效率、填充因子等性能指标不同程度的提升。在有机光电探测器方面,引入的离子液体能促使在与之接触的界面处形成双电层,双电层的形成及离子液体的高导电率使得入射光不必照射有机光电探测器上下电极的重叠区域仍旧可以产生较大的光电流输出,从而可以有效摆脱有机光电探测器对电极材料透光性要求的局限性。同时双电层的形成还将促进有机光电探测器工作层中的电荷分离,进一步提高有机光电探测器的响应率。 本文主要从染料敏化太阳能电池、钙钛矿太阳能电池、有机光电探测器三个方面,综述了离子液体在有机光电转换器件中的国内外应用研究进展,就离子液体对提升有机光电转换效率及其实现器件新功能的工作机理进行了详细分析,并对其未来的应用研究方向进行了展望,为今后进一步设计出更适合有机光电转换领域应用的离子液体提供参考。     

碳材料在钙钛矿太阳能电池中的应用

钙钛矿太阳能电池具有材料成本低廉、生产工艺简单、光电转换效率高等优点,发展前景十分光明。碳材料因其价格低廉、高导电性、疏水性和化学稳定性等特点,被应用在钙钛矿太阳能电池的各个组成部分,用于提高电池性能和降低成本。本文根据应用在钙钛矿太阳能电池中的碳材料的维数进行分类,分别介绍了零维的C60、碳量子点和石墨烯量子点,一维的碳纳米管,二维的石墨烯及其衍生物、石墨炔和三维的石墨等在钙钛矿太阳能电池中的应用,对于将来实现钙钛矿太阳能电池的低成本商业化和大规模制造具有重要意义。     

Assembling Mesoscale‐Structured Organic Interfaces in Perovskite Photovoltaics

Mesoscale‐structured materials offer broad opportunities in extremely diverse applications owing to their high surface areas, tunable surface energy, and large pore volume. These benefits may improve the performance of materials in terms of carrier density, charge transport, and stability. Although metal oxides–based mesoscale‐structured materials, such as TiO₂, predominantly hold the record efficiency in perovskite solar cells, high temperatures (above 400 °C) and limited materials choices still challenge the community. A novel route to fabricate organic‐based mesoscale‐structured interfaces (OMI) for perovskite solar cells using a low‐temperature and green solvent–based process is presented here. The efficient infiltration of organic porous structures based on crystalline nanoparticles allows engineering efficient “n‐i‐p” and “p‐i‐n” perovskite solar cells with enhanced thermal stability, good performance, and excellent lateral homogeneity. The results show that this method is universal for multiple organic electronic materials, which opens the door to transform a wide variety of organic‐based semiconductors into scalable n‐ or p‐type porous interfaces for diverse advanced applications.     

Metal nitride/graphene nanohybrids: general synthesis and multifunctional titanium nitride/graphene electrocatalyst

A facile, efficient, and general strategy is developed for the fabrication of a new class of nanohybrids consisting of nitrogen-doped graphene functionalized with metal nitride nanoparticles. The graphene decorated with titanium nitride nanoparticles is explored for multifunctional electrocatalytic applications, i.e., as a low-cost counter electrode for I(3)(-) reduction in dye-sensitized solar cells and for nicotinamide adenine dinucleotide (NADH) oxidation in dehydrogenase enzyme-based biosensors.     

Interfacial Modification in Organic and Perovskite Solar Cells

Organic bulk heterojunction solar cells (OSCs) and hybrid halide perovskite solar cells (PSCs) are two promising photovoltaic techniques for next‐generation energy conversion devices. The rapid increase in the power conversion efficiency (PCE) in OSCs and PSCs has profited from synergetic progresses in rational material synthesis for photoactive layers, device processing, and interface engineering. Interface properties in these two types of devices play a critical role in dictating the processes of charge extraction, surface trap passivation, and interfacial recombination. Therefore, there have been great efforts directed to improving the solar cell performance and device stability in terms of interface modification. Here, recent progress in interfacial doping with biopolymers and ionic salts to modulate the cathode interface properties in OSCs is reviewed. For the anode interface modification, recent strategies of improving the surface properties in widely used PEDOT:PSS for narrowband OSCs or replacing it by novel organic conjugated materials will be touched upon. Several recent approaches are also in focus to deal with interfacial traps and surface passivation in emerging PSCs. Finally, the current challenges and possible directions for the efforts toward further boosts of PCEs and stability via interface engineering are discussed.     

Integrated Perovskite/Bulk-Heterojunction Organic Solar Cells

The recently emerged integrated perovskite/bulk-heterojunction (BHJ) organic solar cells (IPOSCs) without any recombination layers have generated wide attention. This type of device structure can take the advantages of tandem cells using both perovskite solar and near-infrared (NIR) BHJ organic solar materials for wide-range sunlight absorption and the simple fabrication of single junction cells, as the low bandgap BHJ layer can provide additional light harvesting in the NIR region and the high open-circuit voltage can be maintained at the same time. This progress report highlights the recent developments in such IPOSCs and the possible challenges ahead. In addition, the recent development of perovskite solar cells and NIR organic solar cells is also covered to fully underline the importance and potential of IPOSCs.     

Low-Bandgap Porphyrins for Highly Efficient Organic Solar Cells: Materials,Morphology, and Applications

With developments in materials, thin-film processing, fine-tuning of morphology, and optimization of device fabrication, the performance of organic solar cells (OSCs) has improved markedly in recent years. Designing low-bandgap materials has been a focus in order to maximize solar energy conversion. However, there are only a few successful low-bandgap donor materials developed with near-infrared (NIR) absorption that are well matched to the existing efficient acceptors. Porphyrin has shown great potential as a useful building block for constructing low-bandgap donor materials due to its large conjugated plane and strong absorption. Porphyrin-based donor materials have been shown to contribute to many record-high device efficiencies in small molecule, tandem, ternary, flexible, and OSC/perovskite hybrid solar cells. Specifically, non-fullerene small-molecule solar cells have recently shown a high power conversion efficiency of 12% using low-bandgap porphyrin. All these have validated the great potential of porphyrin derivatives as effective donor materials and made DPPEZnP-TRs a family of best low-bandgap donor materials in the OSC field so far. Here, recent progress in the rational design, morphology, dynamics, and multi-functional applications starting from 2015 will be highlighted to deepen understanding of the structure–property relationship. Finally, some future directions of porphyrin-based OSCs are presented.     

Planar‐Structure Perovskite Solar Cells with Efficiency beyond 21%

Low temperature solution processed planar‐structure perovskite solar cells gain great attention recently, while their power conversions are still lower than that of high temperature mesoporous counterpart. Previous reports are mainly focused on perovskite morphology control and interface engineering to improve performance. Here, this study systematically investigates the effect of precise stoichiometry, especially the PbI₂ contents on device performance including efficiency, hysteresis and stability. This study finds that a moderate residual of PbI₂ can deliver stable and high efficiency of solar cells without hysteresis, while too much residual PbI₂ will lead to serious hysteresis and poor transit stability. Solar cells with the efficiencies of 21.6% in small size (0.0737 cm²) and 20.1% in large size (1 cm²) with moderate residual PbI₂ in perovskite layer are obtained. The certificated efficiency for small size shows the efficiency of 20.9%, which is the highest efficiency ever recorded in planar‐structure perovskite solar cells, showing the planar‐structure perovskite solar cells are very promising.     

Large area dye-sensitized solar cells with titanium based counter electrode

Construction of dye-sensitized solar cell of large area using platinum sputtered titanium metal counter electrode is demonstrated. An impressive increase in the fill factor and consequently the efficiency compared to the conventional platinized conducting glass based counter electrodes result from very low sheet resistance of the titanium plate and a cell of active area 151 cm² with parallel silver collecting grids delivered an efficiency of 7.4%. The possibility of using this technique for commercial production of dye-sensitized solar cells was discussed giving details of fabrication procedure.     

Low-Temperature Chemical Bath Deposition of Conformal and Compact NiOX for Scalable and Efficient Perovskite Solar Modules

A scalable and low-cost deposition of high-quality charge transport layers and photoactive perovskite layers are the grand challenges for large-area and efficient perovskite solar modules and tandem cells. An inverted structure with an inorganic hole transport layer is expected for long-term stability. Among various hole transport materials, nickel oxide has been investigated for highly efficient and stable perovskite solar cells. However, the reported deposition methods are either difficult for large-scale conformal deposition or require a high vacuum process. Chemical bath deposition is supposed to realize a uniform, conformal, and scalable coating by a solution process. However, the conventional chemical bath deposition requires a high annealing temperature of over 400 °C. In this work, an amino-alcohol ligand-based controllable release and deposition of NiO_X using chemical bath deposition with a low calcining temperature of 270 °C is developed. The uniform and conformal in-situ growth precursive films can be adjusted by tuning the ligand structure. The inverted structured perovskite solar cells and large-area solar modules reached a champion PCE of 22.03% and 19.03%, respectively. This study paves an efficient, low-temperature, and scalable chemical bath deposition route for large-area NiO_X thin films for the scalable fabrication of highly efficient perovskite solar modules.     

Perovskite Solar Cells: From Materials to Devices

Perovskite solar cells based on organometal halide light absorbers have been considered a promising photovoltaic technology due to their superb power conversion efficiency (PCE) along with very low material costs. Since the first report on a long‐term durable solid‐state perovskite solar cell with a PCE of 9.7% in 2012, a PCE as high as 19.3% was demonstrated in 2014, and a certified PCE of 17.9% was shown in 2014. Such a high photovoltaic performance is attributed to optically high absorption characteristics and balanced charge transport properties with long diffusion lengths. Nevertheless, there are lots of puzzles to unravel the basis for such high photovoltaic performances. The working principle of perovskite solar cells has not been well established by far, which is the most important thing for understanding perovksite solar cells. In this review, basic fundamentals of perovskite materials including opto‐electronic and dielectric properties are described to give a better understanding and insight into high‐performing perovskite solar cells. In addition, various fabrication techniques and device structures are described toward the further improvement of perovskite solar cells.     

上转换纳米材料及其在提高太阳能电池光电效率中的应用

上转换纳米材料在提高太阳能电池光电效率方面的应用主要通过提高上转换纳米材料的发光性能来实现。利用上转换纳米材料能将2个或2个以上的低能短波光子转换成高能可见光的特性,可以拓宽太阳能电池对光的响应范围,达到提升光电转换效率的目的。主要介绍了上转换纳米材料,包括其发光机制与基质材料的选择。回顾了在近阶段主要使用的热分解法、水热法等制备方法,分析了其他一些制备方法。着重介绍了上转换纳米材料在晶体硅太阳能电池和染敏太阳能电池中的应用。从提升上转换材料发光性的角度来讨论对太阳能电池的研究,并指出了未来上转换纳米材料在太阳能电池中应用的研究重点是利用异质离子掺杂、表面等离子体耦合与量子点敏化等手段提升上转换效率,而染料耦联上转换纳米材料、上转换纳米材料壳包覆等方法也具有很大发展潜力。     

染料敏化太阳能电池用过渡金属化合物对电极的研究进展

由于成本低、制作工艺简单、光电转换效率高, 染料敏化太阳能电池被认为是传统太阳能电池最有力的竞争者之一。染料敏化太阳能电池常用的对电极是Pt电极, Pt价格高, 储量少, 因此寻找一种价格便宜且催化性能较好的材料代替Pt制备对电极是目前的研究热点。过渡金属化合物品种多、制备过程简单、价格低且催化性能好, 近年来受到人们的广泛关注, 是代替Pt制备染料敏化太阳能电池对电极最好的材料之一。本文综述了染料敏化太阳能电池过渡金属化合物对电极的研究现状, 对过渡金属化合物对电极的性能特点及今后研究的重点进行了分析。