Intermediate Phase‐Assisted Sequential Deposition Toward 15.24%‐Efficiency Carbon‐Electrode Cspbi2br Perovskite Solar Cells. Issue 6 (24th February 2022)

• Record Type: Journal Article
• Authors: Zhu, Weidong; Ma, Junxiao; Chai, Wenming; Han, Tianjiao; Chen, Dandan; Xie, Xiaoping; Liu, Gang; Dong, Peng; Xi, He; Chen, Dazheng; Zhang, Jincheng; Zhang, Chunfu; Hao, Yue
• Is Part Of: Solar RRL. Volume 6:Issue 6(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-02-24
• Subjects: all-inorganic perovskites -- carbon-electrode perovskite solar cells -- CsPbI2Br -- intermediate phases -- sequential deposition; Solar energy -- Periodicals; Photovoltaic power generation -- Periodicals; Solar energy -- Research -- Periodicals; Photovoltaic power generation -- Research -- Periodicals; Periodicals; 333.7923
• DOI: 10.1002/solr.202200020
• Languages: English
• ISSNs: 2367-198X

Abstract

Abstract : All‐inorganic perovskite CsPbI2 Br is emerging as a promising absorber material for perovskite solar cells (PSCs) due to its superior photophysical properties and thermal stability. However, there are still many great challenges to obtaining high‐quality, phase‐stable, thick CsPbI2 Br films in ambient air to promote further development of the PSCs. Herein, for the first time, an intermediate phase‐assisted sequential deposition for desired CsPbI2 Br films is proposed. It is carried out by sequentially spin‐coating PbBr2 and CsI precursors onto the substrate in ambient air, during which a Ruddlesden–Popper (R–P) perovskite intermediate phase film composed of a Cs‐Pb‐I‐Br complex is produced. After annealing, the intermediate phase film is transformed into a CsPbI2 Br film consisting of CsPbI2 Br grains and CsBr species through a spinodal decomposition reaction. The as‐obtained CsPbI2 Br film holds full coverage, micro‐sized grains, and excellent phase stability. Moreover, the CsBr species located at grain boundaries can effectively passivate the defects. Therefore, a carbon‐electrode PSC with such a desired CsPbI2 Br film yields the optimized efficiency of 15.24%, coupled with a remarkable photovoltage of 1.312 V and excellent stability in ambient air with relative humidity of 60–70%. The efficiency achieved herein is among the record efficiencies for carbon‐electrode PSCs based on various all‐inorganic perovskites reported currently. Abstract : An intermediate phase‐assisted sequential deposition strategy is demonstrated to prepare a CsPbI2 Br film composed of CsPbI2 Br grains and CsBr species. CsPbI2 Br film possesses full coverage, micro‐sized grains, and excellent phase stability. Meanwhile, CsBr species can passivate defects. Carbon‐electrode perovskite solar cell CsPbI2 Br film yields the record‐high efficiency of 15.24%, coupled with a remarkable photovoltage of 1.312 V and excellent humidity stability.