Wang Han, Qin Zhaotong, Xie Jiangsheng, Zhao Shenghe, Liu Kuan, Guo Xinlu, Li Gang, Lu Xinhui, Yan Keyou, Xu Jianbin
Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, P. R. China.
Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, P. R. China.
Small. 2020 Oct;16(42):e2003098. doi: 10.1002/smll.202003098. Epub 2020 Sep 30.
The crystalline orientation and phase distribution are two important parameters for high-performance 2D perovskite solar cells. Therefore, it is essential to understand how the structure of spacer ligands influences the orientation and phase distribution of resulting 2D perovskite films. In this work, a new member of Dion-Jacobson (DJ) phase 2D perovskites based on trans-1,4-cyclohexanediamine (CHDA) is demonstrated and it is found that the crystalline orientation is self-aligned spontaneously, which is different from the well-known graded distribution in controlled sample with its isomer 1,6-diaminohexane (HDA) as spacer ligand. Grazing incident X-ray scattering suggests that the exact alignment is strongly slantwise to the substrate while it is still beneficial for charge transfer along the vertical structure of devices. The devices can achieve high efficiency up to 15.01% for (CHDA)MA Pb I (n = 4), one of the highest efficiencies reported by now. The encapsulated (CHDA)MA Pb I (n = 4) devices can retain 80.7% efficiency for 270 min under continuous maximum power point tracking. (CHDA)MA Pb I (n = 4) devices can retain 96.5% efficiency under 60 °C and 74.4% efficiency under 70 °C heating for 68 h. The results demonstrate the slantwise aligned DJ phase perovskite solar cells with excellent stability.
晶体取向和相分布是高性能二维钙钛矿太阳能电池的两个重要参数。因此，了解间隔配体的结构如何影响所得二维钙钛矿薄膜的取向和相分布至关重要。在这项工作中，展示了一种基于反式-1,4-环己二胺（CHDA）的Dion-Jacobson（DJ）相二维钙钛矿的新成员，并且发现晶体取向是自发自对准的，这与以其异构体1,6-二氨基己烷（HDA）作为间隔配体的对照样品中众所周知的梯度分布不同。掠入射X射线散射表明，精确的取向相对于衬底强烈倾斜，同时它仍然有利于沿器件的垂直结构进行电荷转移。对于（CHDA）MA Pb I（n = 4），器件可以实现高达15.01%的高效率，这是目前报道的最高效率之一。封装后的（CHDA）MA Pb I（n = 4）器件在连续最大功率点跟踪下270分钟内可保持80.7%的效率。（CHDA）MA Pb I（n = 4）器件在60°C下加热68小时可保持96.5%的效率，在70°C下加热68小时可保持74.4%的效率。结果证明了具有优异稳定性的倾斜排列DJ相钙钛矿太阳能电池。
