Self-healing perovskite solar cells based on copolymer-templated TiO2 electron transport layer

Nakisa Lalpour; Valiollah Mirkhani; Reza Keshavarzi; Majid Moghadam; Shahram Tangestaninejad; Iraj Mohammadpoor-Baltork; Peng Gao

doi:10.1038/s41598-023-33473-9

Self-healing perovskite solar cells based on copolymer-templated TiO₂ electron transport layer

Sci Rep. 2023 Apr 19;13(1):6368. doi: 10.1038/s41598-023-33473-9.

Authors

Nakisa Lalpour¹, Valiollah Mirkhani², Reza Keshavarzi³, Majid Moghadam¹, Shahram Tangestaninejad¹, Iraj Mohammadpoor-Baltork¹, Peng Gao⁴

Affiliations

¹ Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan, 81746-73441, Iran.
² Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan, 81746-73441, Iran. Mirkhani@sci.ui.ac.ir.
³ Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan, 81746-73441, Iran. R.Keshavarzi@chem.ui.ac.ir.
⁴ CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, Fujian, People's Republic of China. p_gao@foxmail.com.

Abstract

Inorganic hole-transport materials (HTMs) such as copper indium disulfide (CIS) have been applied in perovskite solar cells (PSCs) to improve the poor stability of the conventional Spiro-based PSCs. However, CIS-PSCs' main drawback is their lower efficiency than Spiro-PSCs. In this work, copolymer-templated TiO₂ (CT-TiO₂) structures have been used as an electron transfer layer (ETL) to improve the photocurrent density and efficiency of CIS-PSCs. Compared to the conventional random porous TiO₂ ETLs, copolymer-templated TiO₂ ETLs with a lower refractive index improve the transmittance of input light into the cell and therefore enhance the photovoltaic performance. Interestingly, a large number of surface hydroxyl groups on the CT-TiO₂ induce a self-healing effect in perovskite. Thus, they provide superior stability in CIS-PSC. The fabricated CIS-PSC presents a conversion efficiency of 11.08% (Jsc = 23.35 mA/cm², Voc = 0.995, and FF = 0.477) with a device area of 0.09 cm² under 100 mW/cm². Moreover, these unsealed CIS-PSCs retained 100% of their performance after aging tests for 90 days under ambient conditions and even increased from 11.08 to 11.27 over time due to self-healing properties.