Improved perovskite crystallization by antisolvent engineering in tin-perovskite photovoltaics

• Published in: Physical chemistry chemical physics : PCCP 2024-11, Vol.26 (45), p.28715-28723
• Main Authors: Zhang, Xin, Liu, Yu, Chen, Xinyao, Zhang, Chunqian, Wang, Jigang, Cheng, Jin, Li, Junming
• Format: Article
• Language: English
• Subjects: Charge efficiency; Chlorobenzene; Crystal defects; Crystal growth; Crystallization; Current carriers; Dimethyl sulfide; Dimethyl sulfoxide; Lead free; Optoelectronics; Perovskites; Photovoltaic cells; Solvents; Thin films; Vapor pressure
• ISSN: 1463-9076; 1463-9084; 1463-9084
• DOI: 10.1039/d4cp02655a

Tin-based perovskites are considered the candidate with the most potential as lead-free perovskites because of their excellent optoelectronic properties. As a conventional precursor solvent for the fabrication of tin-based perovskite films, dimethyl sulfoxide (DMSO) can form intermediates with SnI 2 , which slows down the crystal growth and thus induces a smooth surface. However, the DMSO solvent exhibits a high donor number and low vapor pressure, whereas the typical anti-solvent chlorobenzene displays a low donor number, resulting in a lack of solvent-cleaning ability and excess DMSO remaining in the perovskite film. Here, we used dimethyl sulfide as an anti-solvent to prepare tin-based perovskite film; it has a high donor number and high vapor pressure. It was found that the introduction of dimethyl sulfide greatly improved the morphology and quality of the perovskite films. In addition, the crystallinity of the thin film improves the transport of charge carriers and reduces defects, resulting in a champion device efficiency of 5.3%. By adding an appropriate proportion of DMS to the anti-solvent, the DMSO remaining in the tin-based perovskite films can be effectively extracted, resulting in films with better crystallography, and the devices have lower trap densities.