Liao Xufeng, Jia Xuefei, Li Weisheng, Lang Xiting, Zhang Jianhua, Zhao Xinyu, Ji Yitong, Du Qingguo, Kuan Chun-Hsiao, Ren Zhiwei, Huang Wenchao, Bai Yang, Zhang Kaicheng, Xiao Chuanxiao, Lin Qianqian, Cheng Yi-Bing, Tong Jinhui
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, PR China.
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, PR China.
Nat Commun. 2025 Jan 30;16(1):1164. doi: 10.1038/s41467-025-56549-8.
All-perovskite tandem solar cells (APTSCs) offer the potential to surpass the Shockley-Queisser limit of single-junction solar cells at low cost. However, high-performance APTSCs contain unstable methylammonium (MA) cation in the tin-lead (Sn-Pb) narrow bandgap subcells. Currently, MA-free Sn-Pb perovskite solar cells (PSCs) show lower performance compared with their MA-containing counterparts. This is due to the high trap density associated with Sn oxidation, which is exacerbated by the rapid crystallization of MA-free Sn-containing perovskite. Here, a multifunctional additive rubidium acetate (RbAC) is proposed to passivate Sn-Pb perovskite. We find that RbAC can suppress Sn oxidation, alleviate microstrain, and improve the crystallinity of the MA-free Sn-Pb perovskite. Consequently, the resultant Sn-Pb PSCs achieve a power conversion efficiency (PCE) of 23.02%, with an open circuit voltage (Voc) of 0.897 V, and a filling factor (FF) of 80.64%, and more importantly the stability of the device is significantly improved. When further integrated with a 1.79-electron volt MA-free wide-bandgap PSC, a 29.33% (certified 28.11%) efficient MA-free APTSCs with a high Voc of 2.22 volts is achieved.
全钙钛矿串联太阳能电池（APTSCs）具有以低成本超越单结太阳能电池的肖克利-奎塞尔极限的潜力。然而，高性能的APTSCs在锡铅（Sn-Pb）窄带隙子电池中含有不稳定的甲铵（MA）阳离子。目前，无MA的Sn-Pb钙钛矿太阳能电池（PSCs）与含MA的同类电池相比性能较低。这是由于与Sn氧化相关的高陷阱密度，而无MA的含Sn钙钛矿的快速结晶会加剧这种情况。在此，提出了一种多功能添加剂醋酸铷（RbAC）来钝化Sn-Pb钙钛矿。我们发现RbAC可以抑制Sn氧化，减轻微应变，并改善无MA的Sn-Pb钙钛矿的结晶度。因此，所得的Sn-Pb PSCs实现了23.02%的功率转换效率（PCE），开路电压（Voc）为0.897 V，填充因子（FF）为80.64%，更重要的是，器件的稳定性得到了显著提高。当进一步与1.79电子伏特的无MA宽带隙PSC集成时，实现了效率为29.33%（认证值为28.11%）、Voc高达2.22伏的无MA APTSCs。
