We demonstrate that using a hole transport bilayer composed of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) and CuI leads to highly efficient and stable inverted, that is, p–i–n, perovskite solar cells (PSCs). The bilayer-based devices had an average power conversion efficiency (PCE) of 19.4% and a maximum PCE of 20.34%. In comparison, devices with a single PTAA interlayer showed an average PCE of 17.7%. Perovskite films fabricated on PTAA/CuI bilayers showed improved crystallinity and larger grain sizes. Data from ultraviolet photoelectron spectroscopy and Mott–Schottky analysis of impedance suggest an increased built-in potential within the device with enhanced upward band bending at the CuI interface. The bilayered HTL devices have minimum current–voltage hysteresis and stable current output at the maximum power point. These devices were stable for more than 4500 h under ambient light in an inert atmosphere.

中文翻译：

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高效稳定的倒钙钛矿太阳能电池的空穴传输双层。

我们证明，使用由聚[双（4-苯基）（2,4,6-三甲基苯基）胺]（PTAA）和CuI组成的空穴传输双层可导致高效且稳定的反型，即p–i–n钙钛矿太阳能电池（PSC）。基于双层的设备的平均功率转换效率（PCE）为19.4％，最大PCE为20.34％。相比之下，具有单个PTAA夹层的设备的平均PCE为17.7％。在PTAA / CuI双层膜上制造的钙钛矿薄膜显示出更高的结晶度和更大的晶粒尺寸。紫外光电子能谱和阻抗的Mott-Schottky分析得出的数据表明，随着CuI界面上的向上频带弯曲的增强，设备中的内置电势增加。双层HTL器件具有最小的电流-电压磁滞和在最大功率点处稳定的电流输出。