Introducing Postmetalation Metal-Organic Framework to Control Perovskite Crystal Growth for Efficient Perovskite Solar Cells

Chi-Kwen Liu; Kuo-Hung Wu; Yen-An Lu; Li-Yin Hsiao; Kuan-Wen Lai; Chih-Wei Chu; Kuo-Chuan Ho

doi:10.1021/acsami.1c22144

Introducing Postmetalation Metal-Organic Framework to Control Perovskite Crystal Growth for Efficient Perovskite Solar Cells

ACS Appl Mater Interfaces. 2021 Dec 22;13(50):60125-60134. doi: 10.1021/acsami.1c22144. Epub 2021 Dec 8.

Authors

Chi-Kwen Liu¹, Kuo-Hung Wu¹, Yen-An Lu¹, Li-Yin Hsiao^{1

2}, Kuan-Wen Lai³, Chih-Wei Chu^{3

4}, Kuo-Chuan Ho^{1

2}

Affiliations

¹ Department of Chemical Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan.
² Advanced Research Center for Green Materials Science and Technology, National Taiwan University, Taipei 10617, Taiwan.
³ Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.
⁴ College of Engineering, Chang Gung University, Taoyuan 33302, Taiwan.

PMID: 34879195
DOI: 10.1021/acsami.1c22144

Abstract

A novel lead-containing metal-organic framework (Pb-MOF) is synthesized through postmetalation of MOF-525. Postmetalation renders lead ions bound with the organic linker of MOF-525, which can serve as nucleation points to promote perovskite crystallization. The introduction of lead postmetalated MOF-525 (Pb-MOF) as a scaffold layer between compact TiO₂ (c-TiO₂) layer and perovskite layer promotes perovskite crystal growth in enlarging crystal grain size with better crystallinity, hence decreasing defect sites in the perovskite layer. Postmetalation of MOF-525 with lead ions allows MAPbI₃ to form a solid crystal structure to facilitate the charge separation between electron transport layer (ETL) and light-harvesting layer so as to resolve the issue of possible vacancies present in MOFs. As a result, the champion perovskite solar cell (PSC) with the introduction of Pb-MOF exhibits a power conversion efficiency (PCE) of 20.87% and better stability (86% PCE retention after 40 days), outperforming the pristine PSC (16.85% PCE, with 52% retention after 40 days) and MOF-525-introduced PSC (18.61% PCE, with 76% retention after 40 days).

Keywords: charge transfer; crystal growth; metal−organic frameworks; perovskite solar cells; postmetalation.