Interfacial defect passivation by novel phosphonium salts yields 22% efficiency perovskite solar cells: Experimental and theoretical evidence

EcoMat

卷:4

Liming Ding¹  Donghwa Lee²  Qunliang Song³  Cunyun Xu³  Wenqi Wang⁴  Zhigang Zang⁴  Le Bai⁴  Jiangzhao Chen⁴  Dongmei He⁴  Baibai Liu⁴  Hongkuan Yuan⁵  Tingwei Zhou⁵ 

[1] Center for Excellence in Nanoscience (CAS), Key Laboratory of Nanosystem and Hierarchical Fabrication (CAS) National Center for Nanoscience and Technology Beijing China;

[2] Department of Materials Science and Engineering Pohang University of Science and Technology Pohang South Korea;

[3] Institute for Clean Energy and Advanced Materials, School of Materials and Energy Southwest University Chongqing China;

[4] Key Laboratory of Optoelectronic Technology & Systems (MoE), College of Optoelectronic Engineering Chongqing University Chongqing China;

[5] School of Physical Science and Technology Southwest University Chongqing China;

关键词: defect passivation;    interface engineering;    methylammonium‐free perovskite;    perovskite solar cells;    phosphonium salts;   

DOI  :  10.1002/eom2.12158

来源: DOAJ

【 摘 要 】

Abstract We modified perovskite/Spiro‐OMeTAD interface by using two novel phosphonium salts containing PF6− counter anion (i.e., ClTPPPF6 and BrTPPPF6). The cation and anion in phosphonium salts possess not only ionic bonds but also coordination bonds with perovskites. The anion and cation vacancies at the surface and GBs of perovskite films can be filled by phosphonium cations and PF6− anions, respectively, resulting in reduced defect density and prolonged carrier lifetimes. The stronger chemical interaction and accordingly better defect passivation were certified for BrTPPPF6 than ClTPPPF6. As a result, the devices modified by ClTPPPF6 and BrTPPPF6 deliver a PCE of 21.73% and 22.15%, respectively, which far exceed 20.6% of the control device. The unsealed BrTPPPF6 modified device maintains 98.2% of its initial efficiency value after thermal aging of 1320 h whereas merely 84.7% for the control device. 96.4% of its original efficiency was retained for BrTPPPF6‐modified device after ambient exposure of 2016 h.

【 授权许可】

Unknown