Chavan Rohit D, Prochowicz Daniel, Bończak Bartłomiej, Fiałkowski Marcin, Tavakoli Mohammad Mahdi, Yadav Pankaj, Patel Manushi J, Gupta Sanjeev K, Gajjar Pankaj N, Hong Chang Kook
Polymer Energy Materials Laboratory, School of Applied Chemical Engineering, Chonnam National University, Gwangju 500-757, South Korea.
Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
ACS Appl Mater Interfaces. 2021 May 5;13(17):20296-20304. doi: 10.1021/acsami.1c01685. Epub 2021 Apr 20.
Fullerene derivatives with a strong electron-accepting ability play a crucial role in enhancing both the performance and stability of perovskite solar cells (PSCs). However, most of the used fullerene molecules are based on [6,6]-phenyl-C-butyric acid methyl ester (PCBM), which limits the device performance due to difficulties in preparing high-quality and uniform thin films. Herein, solution-processable azahomofullerene (AHF) derivatives (abbreviated as AHF-1 and AHF-2) are reported as novel and effective electron-transport layers (ETLs) in p-i-n planar PSCs. Compared to the control PCBM ETL-based PSCs, the devices based on AHFs exhibit higher photovoltaic performances, which is attributed to the enhanced charge-transport properties and improved layer morphology leading to a maximum power conversion efficiency (PCE) of 20.21% in the case of the device based on AHF-2 ETL. Besides, due to the preferable energy band alignment with the perovskite layer, reduced trap states, and suppressed charge recombination, the device with AHF-2 ETL exhibits significantly suppressed hysteresis and improved stability under both ambient and thermal conditions.
具有强吸电子能力的富勒烯衍生物在提高钙钛矿太阳能电池（PSC）的性能和稳定性方面起着关键作用。然而，大多数使用的富勒烯分子基于[6,6]-苯基-C-丁酸甲酯（PCBM），由于难以制备高质量且均匀的薄膜，这限制了器件性能。在此，溶液可加工的氮杂同富勒烯（AHF）衍生物（简称为AHF-1和AHF-2）被报道为p-i-n平面PSC中新型且有效的电子传输层（ETL）。与基于对照PCBM ETL的PSC相比，基于AHF的器件表现出更高的光伏性能，这归因于电荷传输特性的增强和层形貌的改善，基于AHF-2 ETL的器件在这种情况下最大功率转换效率（PCE）达到20.21%。此外，由于与钙钛矿层具有较好的能带对准、减少的陷阱态以及抑制的电荷复合，具有AHF-2 ETL的器件在环境和热条件下均表现出显著抑制的滞后现象和提高的稳定性。
