石墨烯材料在钙钛矿太阳能电池中的研究进展

石墨烯及其衍生物具有独特的材料结构和光电性质,可作为界面修饰层、电子传输层、空穴传输层应用于新型钙钛矿太阳能电池,以提高电池的光电转换效率和性能稳定性。此外,石墨烯透明电极在柔性、半透明或叠层钙钛矿太阳能电池应用中独具优势。本文综述了石墨烯及其衍生物在钙钛矿太阳能电池中的研究进展,指出了未来发展重点。     

倒置钙钛矿太阳能电池电子传输层的研究进展

倒置钙钛矿太阳能电池因具有器件结构简单、迟滞效应小和制造成本低等优点,受到了研究人员越来越多的关注。电子传输层作为钙钛矿太阳能电池中的重要组成部分,其作用主要是传输电子和阻挡空穴。对电子传输层进行改性,可以有效解决其表面粗糙、能级不匹配、电子迁移率低等问题,从而提高器件的光电转换效率。本文从电子传输材料的选择、电子传输层的界面修饰、掺杂作用和改性三方面综述了电子传输层对倒置钙钛矿太阳能电池的性能的影响,并对今后倒置钙钛矿太阳能电池实现商业化做出了展望。     

新一代太阳能电池材料——混合钙钛矿

现代科学技术的发展具有学科之间相互渗透、综合交叉的特点,科学和经济之间的相互作用,推动了当前最活跃的信息科学、生命科学和材料科学的发展,又导致了一系列高新技术和高性能材料的诞生。     

稀土离子上转换发光的研究

综述了上转换发光材料、发光机制中的一些物理问题及影响发光效率的因素，并介质了当前的研究现状。     

掺稀土墩子的上转换光纤激光器

介绍了上转换发光的机理，综述了上转换光纤激光器的发展过程，提出其发展趋势和前景。     

影响稀土频率上转换荧光效率的因素

介绍了上转换荧光机理,综述了提高稀土频率上转换荧光材料效率的途径,主要包括改变基质声子态分布、添加敏化剂、改变基质组分的物料配比及应用新技术(表面荧光增强、抽运方式及新材料合成等)。并结合荧光增强机理,对稀土频率上转换荧光材料的研究动向进行了展望。     

Recent progress in stability of perovskite solar cells

Perovskite solar cells have attracted significant attention in just the past few years in solar cell research fields, where the power conversion efficiency was beyond 22.1%. Now, the most important challenge for perovskite solar cells in practical applications is the stability issue. In this mini-review, we will summarize the degradation mechanism of perovskite solar cells, including the perovskite material itself and also the interfaces. While we also provide our opinion on improving the stability of perovskite solar cells.     

The application of perovskite materials in solar water splitting

Solar water splitting is a promising strategy for sustainable production of renewable hydrogen, and solving the crisis of energy and environment in the world. However, large-scale application of this method is hampered by the efficiency and the expense of the solar water splitting systems. Searching for non-toxic, low-cost, efficient and stable photocatalysts is an important way for solar water splitting. Due to the simplicity of structure and the flexibility of composition, perovskite based photocatalysts have recently attracted widespread attention for application in solar water splitting. In this review, the recent developments of perovskite based photocatalysts for water splitting are summarized. An introduction including the structures and properties of perovskite materials, and the fundamentals of solar water splitting is first provided. Then, it specifically focuses on the strategies for designing and modulating perovskite materials to improve their photocatalytic performance for solar water splitting. The current challenges and perspectives of perovskite materials in solar water splitting are also reviewed. The aim of this review is to summarize recent findings and developments of perovskite based photocatalysts and provide some useful guidance for the future research on the design and development of highly efficient perovskite based photocatalysts and the relevant systems for water splitting.     

Recent progress of dopant-free organic hole-transporting materials in perovskite solar cells

Organic-inorganic hybrid perovskite solar cells have undergone especially intense research and transformation over the past seven years due to their enormous progress in conversion efficiencies. In this perspective, we review the latest developments of conventional perovskite solar cells with a main focus on dopant-free organic hole transporting materials (HTMs). Regarding the rapid progress of perovskite solar cells, stability of devices using dopant-free HTMs are also discussed to help readers understand the challenges and opportunities in high performance and stable perovskite solar cells.     

天然生物材料促进高性能钙钛矿太阳能电池的进展

钙钛矿太阳能电池（PeSCs）因其高效率、低成本和简单的制备工艺而被认为是最有前途的光伏技术之一。PeSCs的能量转换效率和稳定性很大程度上取决于钙钛矿薄膜的质量和器件中的界面,它们是PeSCs非辐射复合损失的主要来源。天然生物材料具有丰富的资源、无毒和生物相容性等优点,在改善PeSCs的钙钛矿层和界面方面显示出巨大的潜力。本文综述了利用天然生物材料实现高性能PeSCs的最新进展。首先讨论天然生物材料在钙钛矿薄膜的形貌优化、缺陷钝化和能级调控方面的作用;同时,讨论利用天然生物材料优化钙钛矿和电荷传输层之间的界面,以及构建可拉伸、可生物相容和可生物降解的电极的策略;最后,展望PeSCs在天然生物材料方面的进一步发展。     

Novel D-A-D type small-molecular hole transport materials for stable inverted perovskite solar cells

Hole transport materials (HTMs), as a critical role in the hole extraction and transportation processes, highly influence the efficiency and stability of perovskite solar cells (PSCs). Despite that several efficient dopant-free HTMs have been reported, there is still no clear structure-property relationship that could give instructions for the rational molecular design of efficient HTMs. Thus, in this work, a series of donor–acceptor-donor (D–A–D) type carbazole-based small molecules, TM-1 to TM-4, have been carefully designed and synthesized. By varing the electron acceptor unit from benzene to pyridine, pyrazine and diazine, their packing structure in single crystals, optical and electronic properties have shown a great difference. While as dopant-free HTM in p-i-n type PSCs, TM-2 improved the device photovoltaic performance with a power conversion efficiency from 15.02% (based on PEDOT:PSS) to 16.13%. Moreover, the unencapsulated device based on TM-2 retains about 80% of its initial efficiency after 500 h storage in ambient environment, showing the superior stability.     

基于钙钛矿材料的新型结构太阳能电池器件

基于钙钛矿材料的太阳能电池是一种受到广泛关注的新型太阳能电池。根据钙钛矿太阳能电池结构的不同将其分为四类,综述了钙钛矿太阳能电池的研究现状和最新进展。详细介绍了各类钙钛矿太阳能电池的结构和性能,分析总结了其优缺点。最后展望了钙钛矿太阳能电池未来的发展趋势。     

Flexible perovskite solar cells:Materials and devices

Flexible perovskite solar cells (FPSCs) are supposed to play an important role in the commercialization of perovskite solar cells due to their unique properties,such as high efficiency,thin thickness and being compatible with roll to roll (R2R) pro-cess for mass production.At present,deformable and lightweight FPSCs have been successfully prepared and applied as power supply by integrating with different wearable and portable electronics,which opens a niche market for photovoltaics.In this mini review,we will introduce the recent progress of FPSCs from the aspect of small-area flexible devices,R2R processed devices with large scale and emerging flexible cells with deformability and stretchability.Finally,conclusion and outlook are provided.     

Designing novel thin film polycrystalline solar cells for high efficiency: sandwich CIGS and heterojunction perovskite

Heterojunction and sandwich architectures are two new-type structures with great potential for solar cells. Specifically, the heterojunction structure possesses the advantages of efficient charge separation but suffers from band offset and large interface recombination; the sandwich configuration is favorable for transferring carriers but requires complex fabrication process. Here, we have designed two thin-film polycrystalline solar cells with novel structures:sandwich CIGS and heterojunction perovskite, referring to the advantages of the architectures of sandwich perovskite (standard) and heterojunction CIGS (standard) solar cells, respectively. A reliable simulation software wxAMPS is used to investigate their inherent characteristics with variation of the thickness and doping density of absorber layer. The results reveal that sandwich CIGS solar cell is able to exhibit an optimized efficiency of 20.7%, which is much higher than the standard heterojunction CIGS structure (18.48%). The heterojunction perovskite solar cell can be more efficient employing thick and doped perovskite films (16.9%) than these typically utilizing thin and weak-doping/intrinsic perovskite films (9.6%). This concept of structure modulation proves to be useful and can be applicable for other solar cells.     

The investigation of an amidine-based additive in the perovskite films and solar cells

Here, we introduced acetamidine (C₂H₃N₂H₃, Aa)-based salt as an additive in the fabrication of perovskite (CH₃NH₃PbI₃) layer for perovskite solar cells. It was found that as an amidine-based salt, this additive successfully enhanced the crystallinity of CH₃NH₃PbI₃ and helped to form smooth and uniform films with comparable grain size and full coverage. Besides, perovskite film with additive showed a much longer carrier lifetime and an obviously enhanced open-circuit voltage in the corresponding devices, indicating that the acetamidine-based salt can reduce the carrier recombination in both the film and device. We further demonstrate a promising perovskite device based on acetamidine salt by using a configuration of ITO/TiO₂/Perovskite/Spiro-OMeTAD/Au under <150℃ fabrication condition. A power conversion efficiency (PCE) of 16.54% was achieved, which is much higher than the control device without acetamidine salt. These results present a simple method for film quality optimization of perovskite to further improve photovoltaic performances of perovskite solar cells, which may also benefit the exploration of A cation in perovskite materials.     

Applications of cesium in the perovskite solar cells

Perovskite solar cells have experienced an unprecedented rapid development in the power conversion efficiency (PCE) during the past 7 years, and the record PCE has been already comparable to the traditional polycrystalline silicon solar cells. Presently, it is more urgent to address the challenge on device stability for the future commercial application. Recently, the inorganic cesium lead halide perovskite has been intensively studied as one of the alternative candidates to improve device stability through controlling the phase transition. The cesium (Cs)-doped perovskites show more superior stability comparing with organic methylammonium (MA) lead halide perovskite or formamidinium (FA) lead halide perovskite. Here, recent progress of the inorganic cesium application in organic-inorganic perovskite solar cells (PSCs) is highlighted from the viewpoints of the device efficiency and the device stability.