Department of Materials Science and Engineering , Nanchang University , 999 Xuefu Avenue , Nanchang 330031 , China.
National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China.
ACS Appl Mater Interfaces. 2019 Sep 11;11(36):33515-33524. doi: 10.1021/acsami.9b12961. Epub 2019 Aug 27.
In this work, a novel back contact interface engineering is developed for inverted planar perovskite solar cells, in which a tetrafluoroterephthalic acid (TFTPA) interlayer is inserted between CHNHPbI and PCBM to strengthen the interface contact. Benefiting from the strong Coulombic interactions between positive electron-poor tetrafluoroterephthalate moieties and negative electron-rich fullerene molecules, as well as the coordinate effect between -COOH groups of TFTPA and Pb ions of perovskites surface, a tightly jointing and defect-passivated CHNHPbI/PCBM interface is formed. The strengthened CHNHPbI/PCBM back contact can significantly facilitate electron transport and simultaneously diminish the charge accumulation and recombination. Therefore, power conversion efficiency (PCE) of the TFTPA device is up to 19.39%, whereas the hysteresis effect is weak, and the PCE is improved by 20.4% compared with the control device which does not have a TFTPA interlayer. Particularly, the moisture stability of the TFTPA device is greatly improved as compared to the control device. Our findings illustrate that the back contact interface engineering is an important and promising approach for inverted planar perovskite solar cells.
在这项工作中，为倒置平面钙钛矿太阳能电池开发了一种新型背接触界面工程，其中在 CHNHPbI 和 PCBM 之间插入四氟对苯二甲酸（TFTPA）层，以增强界面接触。得益于正电子缺电子四氟对苯二甲酸部分和负电子富富勒烯分子之间的强库仑相互作用，以及 TFTPA 的-COOH 基团和钙钛矿表面的 Pb 离子之间的配位效应，形成了紧密结合和缺陷钝化的 CHNHPbI/PCBM 界面。增强的 CHNHPbI/PCBM 背接触可以显著促进电子传输，同时减少电荷积累和复合。因此，TFTPA 器件的功率转换效率（PCE）高达 19.39%，而迟滞效应较弱，与没有 TFTPA 层的对照器件相比，PCE 提高了 20.4%。特别是，与对照器件相比，TFTPA 器件的水分稳定性得到了极大提高。我们的研究结果表明，背接触界面工程是倒置平面钙钛矿太阳能电池的一种重要且有前途的方法。
