Wang Huaxin, Li Haiyun, Cai Wensi, Zhang Pengfei, Cao Siliang, Chen Zhenyu, Zang Zhigang
Key Laboratory of Optoelectronic Technology & Systems (Ministry of Education), Chongqing University, Chongqing 400044, China.
Nanoscale. 2020 Jul 21;12(27):14369-14404. doi: 10.1039/d0nr03408h. Epub 2020 Jul 3.
Parallel to the flourishing of inorganic-organic hybrid perovskite solar cells (PSCs), the development of inorganic cesium-based metal halide PSCs (CsPbX) is accelerating, with power conversion efficiency (PCE) values of over 20% being obtained. Although CsPbX possesses numerous merits, such as superior thermal stability and great potential for use in tandem solar cells, severe challenges remain, such as its phase instability, trap state density, and absorption range limitations, hindering further performance improvements and commercialization. This review summarizes challenges and strategies relating to each device functional layer and their integration for the purposes of performance improvement and commercialization, utilizing the fundamental configuration of a perovskite photo-absorption layer, electron transport layer (ETL), and hole transport layer (HTL ). In detail, we first analyze comprehensively strategies for designing high-quality CsPbX perovskite films, including precursor engineering, element doping, and post-treatment, followed by discussing the precise control of the CsPbX film fabrication process. Then, we introduce and analyze the carrier dynamics and interfacial modifications of inorganic ETLs, such as TiO, SnO, ZnO, and other typical organic ETLs with p-i-n configuration. The pros and cons of inorganic and organic HTLs are then discussed from the viewpoints of stability and band structure. Subsequently, promising candidates, i.e., HTL-free carbon-electrode-based inorganic CsPbX PSCs, that meet the "golden triangle" criteria used by the PSC community are reviewed, followed by discussion of other obstacles, such as hysteresis and large-scale fabrication, that lie on the road toward PSC commercialization. Finally, some perspectives relating to solutions to development bottlenecks are proposed, with the attempt to gain insight into CsPbX PSCs and inspire future research prospects.
与无机-有机杂化钙钛矿太阳能电池（PSC）蓬勃发展并行的是，无机铯基金属卤化物PSC（CsPbX）的发展正在加速，其功率转换效率（PCE）值已超过20%。尽管CsPbX具有许多优点，如卓越的热稳定性以及在串联太阳能电池中应用的巨大潜力，但仍存在严峻挑战，例如其相不稳定性、陷阱态密度和吸收范围限制，这阻碍了性能的进一步提升和商业化。本综述总结了与每个器件功能层及其集成相关的挑战和策略，旨在通过利用钙钛矿光吸收层、电子传输层（ETL）和空穴传输层（HTL）的基本结构来提高性能并实现商业化。具体而言，我们首先全面分析设计高质量CsPbX钙钛矿薄膜的策略，包括前驱体工程、元素掺杂和后处理，随后讨论CsPbX薄膜制备过程的精确控制。然后，我们介绍并分析无机ETL（如TiO、SnO、ZnO）以及其他具有p-i-n结构的典型有机ETL的载流子动力学和界面修饰。接着从稳定性和能带结构的角度讨论无机和有机HTL的优缺点。随后，综述了符合PSC领域使用的“金三角”标准的有前景的候选者，即无HTL的基于碳电极的无机CsPbX PSC，接着讨论了PSC商业化道路上的其他障碍，如滞后现象和大规模制备。最后，提出了一些与解决发展瓶颈相关的观点，试图深入了解CsPbX PSC并激发未来的研究前景。
