Enhancing Charge Transport of 2D Perovskite Passivation Agent for Wide‐Bandgap Perovskite Solar Cells Beyond 21%. Issue 6 (23rd March 2020)

• Record Type: Journal Article
• Authors: Ye, Jiselle Y.; Tong, Jinhui; Hu, Jun; Xiao, Chuanxiao; Lu, Haipeng; Dunfield, Sean P.; Kim, Dong Hoe; Chen, Xihan; Larson, Bryon W.; Hao, Ji; Wang, Kang; Zhao, Qian; Chen, Zheng; Hu, Huamin; You, Wei; Berry, Joseph J.; Zhang, Fei; Zhu, Kai
• Is Part Of: Solar RRL. Volume 4:Issue 6(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-03-23
• Subjects: charge transports -- passivation agents -- perovskites -- solar cells -- 2D; Solar energy -- Periodicals; Photovoltaic power generation -- Periodicals; Solar energy -- Research -- Periodicals; Photovoltaic power generation -- Research -- Periodicals; Periodicals; 333.7923
• DOI: 10.1002/solr.202000082
• Languages: English
• ISSNs: 2367-198X

Abstract

Abstract : The replacement of a small amount of organic cations with bulkier organic spacer cations in the perovskite precursor solution to form a 2D perovskite passivation agent (2D‐PPA) in 3D perovskite thin films has recently become a promising strategy for developing perovskite solar cells (PSCs) with long‐term stability and high efficiency. However, the long, bulky organic cations often form a barrier, hindering charge transport. Herein, for the first time, 2D‐PPA engineering based on wide‐bandgap (≈1.68 eV) perovskites are reported. Pentafluorophenethylammonium (F5PEA + ) is introduced to partially replace phenylethylammonium (PEA + ) as the 2D‐PPA, forming a strong noncovalent interaction between the two bulky cations. The charge transport across and within the planes of pure 2D perovskites, based on mixed ammoniums, increases by a factor of five and three compared with that of mono‐cation 2D perovskites, respectively. The perovskite films based on mixed‐ammonium (F5PEA + ‐PEA + ) 2D‐PPA exhibit similar surface morphology and crystal structure, but longer carrier lifetime, lower exciton binding energy, less trap density and higher conductivity, in comparison with those using mono‐cation (PEA + ) 2D‐PPA. The performance of PSCs based on mixed‐cation 2D‐PPA is enhanced from 19.58% to 21.10% along with improved stability, which is the highest performance for reported wide‐bandgap PSCs. Abstract : The introduction of F5PEA + to partially replace PEA + as the 2D perovskite passivation agent, with a strong noncovalent interaction between the two bulky cations and enhanced charge transport, is reported to improve the performance (from 19.58% to 21.10%) and stability of the corresponding wide‐bandgap perovskite solar cells.