Enhancing the performance and stability of carbon-based CsPbI2Br perovskite solar cells via tetrabutylammonium iodide surface passivation

• Published in: Solar energy 2021-12, Vol.230, p.666-674
• Main Authors: Zheng, Shenshen, Wang, Haobin, Wei, Peng, Chen, Huamei, Xie, Yahong
• Format: Article
• Language: English
• Subjects: Acetic acid; All-inorganic PSCs; Atmospheric conditions; Carbon; Carrier lifetime; Commercialization; Crystal defects; CsPbI2Br; Efficiency; Energy conversion efficiency; Ethyl acetate; Gradient annealing; Inorganic carbon; Iodides; Performance enhancement; Perovskites; Photoelectricity; Photovoltaic cells; Relative humidity; Solar cells; Solar energy; Surface passivation; Tin dioxide
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2021.10.074

The carbon-based CsPbI2Br perovskite solar cells via tetrabutylammonium iodide surface passivation, which helps the cells achieve a champion efficiency of 12.29% and enhanced stability. [Display omitted] •All-inorganic C-PSCs were successfully prepared at lower temperature.•Improved the performance of CsPbI2Br PSCs through TBAI surface passivation.•All operations are carried out under atmospheric conditions.•The carbon-based HTM-free CsPbI2Br PSCs achieved a champion efficiency of 12.29%.•The device showed enhanced long-term air stability in ambient air. All-inorganic carbon-based perovskite solar cells (C-PSCs) with CsPbI2Br as photosensitizer have attracted great attention due to their low cost, high efficiency, and good stability. However, the CsPbI2Br film prepared by the solution method usually has many defects, which reduces the charge extraction rate and photoelectric performance. In this paper, intermediate gradient annealing and antisolvent ethyl acetate treatment are combined to prepare CsPbI2Br films with good crystallinity and few voids. The surface of the obtained CsPbI2Br film is then treated using tetrabutylammonium iodide (TBAI), which can interact with the Pb-I framework to passivate defect states and extend the carrier lifetime. Finally, the champion power conversion efficiency (PCE) of the optimized C-PSCs with a structure of FTO/SnO2/CsPbI2Br/carbon electrode prepared in the air reach 12.29%. At the same time, TBAI molecules also effectively enhance the stability of the PSCs, and the unencapsulated device can still maintain 90% of the initial efficiency after 300 h of storage in an ambient air atmosphere with a relative humidity of 20%-30%. This work provides a simple and effective strategy for the preparation of cheap, high-performance, and stable all-inorganic C-PSCs under atmospheric conditions, and also increases the feasibility of PSCs commercialization.