Morphology and Performance Enhancement through the Strong Passivation Effect of Amphoteric Ions in Tin-based Perovskite Solar Cells

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 19; no. 39; p. e2302418
• Main Authors: Ryu, Du Hyeon, Khan, Nasir, Park, Jong-Goo, Paik, Dooam, Kang, Bong Joo, Jeon, Nam Joong, Lee, Seungjin, Lee, Hang Ken, Lee, Sang Kyu, Shin, Won Suk, Lee, Jong-Cheol, Kim, Hyungjun, Hong, Ki-Ha, Im, Sang Hyuk, Song, Chang Eun
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.09.2023
• Subjects: Crystallization; Density functional theory; Energy conversion efficiency; Lead compounds; Metal halides; Morphology; Nanotechnology; Nucleation; Optoelectronics; Performance enhancement; Perovskites; Photovoltaic cells; Solar cells; amphoteric ions; crystallinity; morphology; tin-based perovskite solar cells; defect passivation
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202302418

Despite the optoelectronic similarities between tin and lead halide perovskites, the performance of tin-based perovskite solar cells remains far behind, with the highest reported efficiency to date being ≈14%. This is highly correlated to the instability of tin halide perovskite, as well as the rapid crystallization behavior in perovskite film formation. In this work, l-Asparagine as a zwitterion plays a dual role in controlling the nucleation/crystallization process and improving the morphology of perovskite film. Furthermore, tin perovskites with l-Asparagine show more favorable energy-level matching, enhancing the charge extraction and minimizing the charge recombination, leading to an enhanced power conversion efficiency of 13.31% (from 10.54% without l-Asparagine) with remarkable stability. These results are also in good agreement with the density functional theory calculations. This work not only provides a facile and efficient approach to controlling the crystallization and morphology of perovskite film but also offers guidelines for further improved performance of tin-based perovskite electronic devices.