近日，武汉大学物质与技术学院的柯维俊&方国家及其研究小组取得一项新进展。经过不懈努力，他们发现天冬氨酸一体化掺杂策略可实现高效的全钙钛矿叠层电池。相关研究成果已于2023年11月8日在国际权威学术期刊《自然》上发表。

在这项研究中，研究人员重点关注了窄带隙子电池，并为其设计了一种综合性的掺杂策略。他们通过将天冬氨酸盐酸盐(AspCl)引入到底部聚(3,4-乙烯二氧噻吩)-聚(苯乙烯磺酸盐)和块状钙钛矿层中，并进行了AspCl后处理。结果发现，仅使用单一的AspCl添加剂便能有效地抑制缺陷，降低Sn⁴⁺杂质，并导致费米能级的位移。此外，AspCl-Sn /Pb碘化物与AspCl-AspCl之间的强大分子键起到了强化结构的作用，从而增强了Sn-Pb钙钛矿的稳定性。

最终，当在Sn-Pb钙钛矿太阳能电池中掺杂AspCl后，单结电池的功率转换效率达到了22.46%，而叠层电池的功率转换效率更是高达27.84%（27.62%稳定，27.34%经过认证）。这些电池在充满氮气的手套箱中储存2000小时后，其效率保持率依然高达95%。这些结果表明，全面采用AspCl掺杂策略是提高单结Sn-Pb钙钛矿太阳能电池及其叠层电池效率和稳定性的有效方法。

据悉，全钙钛矿串联太阳能电池具有超越单结太阳能电池的Shockley-Queisser极限的潜力。然而，在实际应用中，这些电池仍面临着一些挑战。其中主要的问题是全钙钛矿叠层电池中的混合锡铅(Sn-Pb)窄带隙钙钛矿子电池的性能欠佳，并且存在稳定性问题。

附：英文原文

Title: Aspartate all-in-one doping strategy enables efficient all-perovskite tandems

Author: Zhou, Shun, Fu, Shiqiang, Wang, Chen, Meng, Weiwei, Zhou, Jin, Zou, Yuanrong, Lin, Qingxian, Huang, Lishuai, Zhang, Wenjun, Zeng, Guojun, Pu, Dexin, Guan, Hongling, Wang, Cheng, Dong, Kailian, Cui, Hongsen, Wang, Shuxin, Wang, Ti, Fang, Guojia, Ke, Weijun

Issue&Volume: 2023-11-08

Abstract: All-perovskite tandem solar cells hold great promise in surpassing the Shockley–Queisser limit for single-junction solar cells. However, the practical use of these cells is currently hampered by the subpar performance and stability issues associated with mixed tin–lead (Sn–Pb) narrow-bandgap perovskite subcells in all-perovskite tandems. In this study, we focus on the narrow-bandgap subcells and develop an all-in-one doping strategy for them. We introduce aspartate hydrochloride (AspCl) into both the bottom poly(3,4-ethylene dioxythiophene)–poly(styrene sulfonate) and bulk perovskite layers, followed by another AspCl posttreatment. We show that a single AspCl additive can effectively passivate defects, reduce Sn⁴⁺ impurities and shift the Fermi energy level. Additionally, the strong molecular bonding of AspCl–Sn/Pb iodide and AspCl–AspCl can strengthen the structure and thereby improve the stability of Sn–Pb perovskites. Ultimately, the implementation of AspCl doping in Sn–Pb perovskite solar cells yielded power conversion efficiencies of 22.46% for single-junction cells and 27.84% (27.62% stabilized and 27.34% certified) for tandems with 95% retention after being stored in an N₂-filled glovebox for 2,000 h. These results suggest that all-in-one AspCl doping is a favourable strategy for enhancing the efficiency and stability of single-junction Sn–Pb perovskite solar cells and their tandems.

DOI: 10.1038/s41586-023-06707-z

Source: https://www.nature.com/articles/s41586-023-06707-z