Successful commercialization of perovskite solar cells (PSCs) in the near future will require the fabrication of cells with high efficiency and long-term stability. Despite their good processability at low temperatures, the majority of organic conductors employed in the fabrication of high-efficiency PSCs [e.g., 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene (spiro-OMeTAD) and poly(triaryl amine) (PTAA)] have low thermal stability. In order to fabricate PSCs with excellent thermal stability, both the constituent material itself and the interface between the constituents must be thermally stable. In this work, we focused on copper phthalocyanine (CuPC) as a model hole-transporting material (HTM) for thermally stable PSCs since CuPC is known to possess excellent thermal stability and interfacial bonding properties. The CuPC-based PSCs recorded a high power conversion efficiency (PCE) of ∼18% and maintained 97% of their initial efficiency for more than 1000 h of thermal annealing at 85 °C. Moreover, the device was stable under thermal cycling tests (50 cycles, −45 to 85 °C). The high PCE and high thermal stability observed in the CuPC-PSCs were found to arise as a result of the strong interfacial and conformal coating present on the surface of the perovskite facets, located between CuPC and the perovskite layer. These results will provide an important future direction for the development of highly efficient and thermally stable PSCs.

中文翻译：

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卤化钙钛矿与铜酞菁之间的工程界面结构，可实现高效，稳定的钙钛矿太阳能电池

钙钛矿太阳能电池（PSC）的成功商业化将在不久的将来要求制造具有高效率和长期稳定性的电池。尽管它们在低温下具有良好的可加工性，但大多数有机导体仍用于制造高效PSC [例如，2,2'，7,7'-四（N，N -di- p-甲氧基苯胺）-9,9'-螺二芴（spiro-OMeTAD）和聚三芳基胺（PTAA）]的热稳定性低。为了制造具有优异热稳定性的PSC，组成材料本身以及组成之间的界面都必须是热稳定的。在这项工作中，我们专注于铜酞菁（CuPC）作为热稳定PSC的模型空穴传输材料（HTM），因为已知CuPC具有出色的热稳定性和界面粘合性能。基于CuPC的PSC记录了约18％的高功率转换效率（PCE），并在85°C下进行了1000多个小时的热退火，可保持其初始效率的97％。此外，该器件在热循环测试（50个循环，-45至85°C）下稳定。发现在CuPC-PSC中观察到的高PCE和高热稳定性是由于位于CuPC和钙钛矿层之间的钙钛矿小平面表面上存在牢固的界面和共形涂层的结果。这些结果将为开发高效，热稳定的PSC提供重要的未来方向。