Guan Nianci, Deng Zhaoqi, Zou Keren, Liu Yunfeng, Wang Yibo, Yang Xue-Chun, Jiao Zheng
School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, P. R. China.
24th Research Institute of China Electronics Technology Group Corporation, Chongqing 400060, China.
ACS Appl Mater Interfaces. 2025 Aug 20;17(33):47649-47658. doi: 10.1021/acsami.5c08236. Epub 2025 Aug 11.
Perovskite solar cells (PSCs) have garnered widespread attention owing to their outstanding power conversion efficiencies (PCEs), which currently exceed 27%. Good interfacial contact and energy level alignment between the perovskite layer and the hole transport layer (HTL) are essential for efficient charge-carrier collection and nonradiative recombination minimization. Spiro-OMeTAD is commonly employed as the HTL in high-performance planar PSCs. Because of its intrinsically low hole mobility, spiro-OMeTAD is frequently doped with the p-type additive lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) to increase electrical conductivity. However, the pronounced hygroscopicity of Li-TFSI leads to moisture uptake, which accelerates perovskite degradation and adversely affects device performance. Therefore, constructing a perovskite/spiro-OMeTAD interface with improved stability is essential yet challenging. Herein, the perovskite/spiro-OMeTAD interface was modified using two dipole molecules that promoted effective band alignment at the interface. Furthermore, introducing oxygen dipole (O-Dipoles) molecules effectively suppressed trap states, resulting in efficient hole extraction at the perovskite/HTL interface. Consequently, the O-Dipoles-modified device was more efficient and stable than the control. This study emphasizes the importance of interfacial molecular design in simultaneously maximizing the efficiency and long-term stability of PSCs.
钙钛矿太阳能电池（PSCs）因其出色的功率转换效率（PCEs）而受到广泛关注，目前该效率已超过27%。钙钛矿层与空穴传输层（HTL）之间良好的界面接触和能级匹配对于高效电荷载流子收集和最小化非辐射复合至关重要。在高性能平面PSCs中，Spiro-OMeTAD通常用作HTL。由于其固有空穴迁移率低，Spiro-OMeTAD经常掺杂p型添加剂双（三氟甲磺酰）亚胺锂（Li-TFSI）以提高电导率。然而，Li-TFSI显著的吸湿性会导致水分吸收，加速钙钛矿降解并对器件性能产生不利影响。因此，构建具有更高稳定性的钙钛矿/Spiro-OMeTAD界面至关重要但具有挑战性。在此，使用两种偶极分子修饰钙钛矿/Spiro-OMeTAD界面，促进了界面处有效的能带排列。此外，引入氧偶极（O-Dipoles）分子有效抑制了陷阱态，从而在钙钛矿/HTL界面实现了高效的空穴提取。因此，O-Dipoles修饰的器件比对照器件更高效、更稳定。本研究强调了界面分子设计对于同时最大化PSCs效率和长期稳定性的重要性。
