Herein, the important role of the isomer purity of hole‐transporting materials (HTMs) in achieving high‐performance perovskite solar cells (PSCs) is highlighted. The isomer‐pure 2,9,16,24‐tetra‐n‐butyl‐Zn(II) phthalocyanine (RE‐ZnBu₄Pc) is directly synthesized through a ring expansion method, without any further purification. The ground‐state absorption, fluorescence and thermal properties of RE‐ZnBu₄Pc and the isomer mixture ZnBu₄Pc, along with their hole mobilities and film morphologies are investigated, proving that RE‐ZnBu₄Pc can be the more efficient HTM. The devices based on RE‐ZnBu₄Pc, as dopant‐free HTMs, achieve a higher average power conversion efficiency (PCE of 11.49% ± 0.67%) and more stability at 25 °C and under 75% relative humidity than that of isomer mixture ZnBu₄Pc (PCE of 9.51% ± 1.15%). RE‐ZnBu₄Pc‐based PSCs also show better reproducibility in the fabrication process. This study demonstrates that better device performance can be expected for PSCs with isomer‐pure HTM materials.

中文翻译：

---

平面钙钛矿太阳能电池中基于异构体纯四丁基取代的酞菁锌（II）酞菁的无掺杂空穴传输层。

本文强调了空穴传输材料（HTM）的异构体纯度在实现高性能钙钛矿太阳能电池（PSC）中的重要作用。异构体纯的2,9,16,24-四正丁基-Zn （II）酞菁（RE- ZnBu ₄ Pc）是通过扩环法直接合成的，无需进一步纯化。研究了RE- ZnBu ₄ Pc和异构体混合物ZnBu ₄ Pc的基态吸收，荧光和热学性质，以及它们的空穴迁移率和薄膜形态，证明RE- ZnBu ₄ Pc可以成为更有效的HTM。基于RE ‐ZnBu ₄的设备与异构体混合物ZnBu ₄ Pc（PCE为9.51％）相比，作为无掺杂HTM的Pc具有更高的平均功率转换效率（PCE为11.49％±0.67％），并且在25°C和75％的相对湿度下具有更高的稳定性。±1.15％）。基于RE ZnBu ₄ Pc的PSC在制造过程中也显示出更好的可重复性。这项研究表明，使用纯异构HTM材料的PSC有望获得更好的设备性能。