Shi Zhuojie, Liu Shunchang, Luo Ran, Ma Jianpeng, Tian Hao, Wang Xi, Dong Zijing, Guo Xiao, Chen Jinxi, Feng Jiangang, Xiao Chuanxiao, Wu Yuchen, Hu Wenping, Hou Yi
Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University Fuzhou, Fuzhou 350207, China.
Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585, Singapore.
J Am Chem Soc. 2025 Jan 8;147(1):1055-1062. doi: 10.1021/jacs.4c14473. Epub 2024 Dec 19.
The surface passivation with the heterostructure of the 2D/3D stack has been widely used for boosting the efficiency of n-i-p perovskite solar cells (PSCs). However, the disordered quantum well width distribution of 2D perovskites leads to energy landscape inhomogeneity and crystalline instability, which limits the further development of n-i-p PSCs. Here, a versatile approach, ligand-mediated surface passivation, was developed to produce a phase-pure 2D perovskite passivation layer with a homogeneous energy landscape by dual-ligand codeposition. The preferential adsorption of 3,6-dimethyl-carbazole-9-ethylammonium iodide with a large molecular size and lower adsorption energy could regulate the surface reaction between the -fluorophenylethylammonium iodide and perovskite surface, resulting in a 2D perovskite with a narrow quantum well distribution and a uniform surface potential distribution. Beyond this, the preservation of the surface-confined 2D passivation layer retained a higher electric field at the interface of perovskite and the hole transport layer. As a result, the champion device reached an efficiency of 25.86% for the 0.05 cm device and 25.08% for the 1 cm device, with enhanced operational stability (T > 1000 h) and much better thermal stability. Our work provides deeper insights into efficient and stable 2D passivation for PSCs.
二维/三维堆叠异质结构的表面钝化已被广泛用于提高n-i-p型钙钛矿太阳能电池（PSC）的效率。然而，二维钙钛矿无序的量子阱宽度分布导致了能量景观的不均匀性和晶体不稳定性，这限制了n-i-p型PSC的进一步发展。在此，我们开发了一种通用方法——配体介导的表面钝化，通过双配体共沉积制备出具有均匀能量景观的纯相二维钙钛矿钝化层。具有较大分子尺寸和较低吸附能的3,6-二甲基咔唑-9-乙基碘化铵的优先吸附可以调节碘化氟苯基乙基铵与钙钛矿表面之间的表面反应，从而得到具有窄量子阱分布和均匀表面电位分布的二维钙钛矿。除此之外，表面受限的二维钝化层的保留在钙钛矿与空穴传输层的界面处保持了较高的电场。结果，对于0.05 cm²的器件，冠军器件的效率达到25.86%，对于1 cm²的器件，效率达到25.08%，同时具有增强的操作稳定性（T > 1000 h）和更好的热稳定性。我们的工作为PSC的高效稳定二维钝化提供了更深入的见解。
