Choi Da-Seul, Kwon Sung-Nam, Na Seok-In
Graduate School of Flexible and Printable Electronics, LANL-JBNU Engineering Institute-Korea, Jeonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si 54896, Korea.
Nanomaterials (Basel). 2020 May 31;10(6):1082. doi: 10.3390/nano10061082.
PCBM is commonly used in perovskite solar cells (PSC) as the electron transport material (ETM). However, PCBM film has various disadvantages, such as its low coverage or the many pinholes that appear due to its aggregation behavior. These faults may lead to undesirable direct contact between the metal cathode and perovskite film, which could result in charge recombination at the perovskite/metal interface. In order to overcome this problem, three alternative non-fullerene electron materials were applied to inverted PSCs; they were evaluated on suitability as electron transport layers. The roles and effects of these non-fullerene ETMs on device performance were studied using photoluminescence (PL) measurements, field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), internal resistance in PSC measurements, and conductive atomic force microscopy (C-AFM). It was found that one of the tested materials, IT-4f, showed excellent electron extraction ability and was associated with reduced recombination. The PSC with IT-4f as the ETM produced better cell-performance; it had an average PCE of 11.21%, which makes it better than the ITIC and COi8DFIC-based devices. Finally, IT-4f was compared with PCBM; it was found that the two materials have quite comparable efficiency and stability levels.
PCBM通常作为电子传输材料（ETM）用于钙钛矿太阳能电池（PSC）。然而，PCBM薄膜存在各种缺点，例如其覆盖率低或由于其聚集行为而出现的许多针孔。这些缺陷可能导致金属阴极与钙钛矿薄膜之间出现不良的直接接触，这可能会导致在钙钛矿/金属界面处发生电荷复合。为了克服这个问题，三种替代的非富勒烯电子材料被应用于倒置PSC；对它们作为电子传输层的适用性进行了评估。使用光致发光（PL）测量、场发射扫描电子显微镜（FE-SEM）、原子力显微镜（AFM）、PSC测量中的内阻以及导电原子力显微镜（C-AFM）研究了这些非富勒烯ETM对器件性能的作用和影响。结果发现，其中一种测试材料IT-4f表现出优异的电子提取能力，并与减少的复合相关。以IT-4f作为ETM的PSC产生了更好的电池性能；其平均光电转换效率（PCE）为11.21%，这使其优于基于ITIC和COi8DFIC的器件。最后，将IT-4f与PCBM进行了比较；发现这两种材料具有相当可比的效率和稳定性水平。
