Quasi‐2D Bilayer Surface Passivation for High Efficiency Narrow Bandgap Perovskite Solar Cells. Issue 20 (16th March 2022)

• Record Type: Journal Article
• Authors: Yu, Danni; Wei, Qi; Li, Hansheng; Xie, Junhan; Jiang, Xianyuan; Pan, Ting; Wang, Hao; Pan, Mengling; Zhou, Wenjia; Liu, Weimin; Chow, Philip C. Y.; Ning, Zhijun
• Is Part Of: Angewandte Chemie international edition. Volume 61:Issue 20(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-16
• Subjects: Bilayers -- Perovskites -- Solar Cells -- Surface Passivation -- Tin-Lead Surface; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202202346
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The combination of comprehensive surface passivation and effective interface carriers transfer plays a critical role in high‐performance perovskite solar cells. A 2D structure is an important approach for surface passivation of perovskite film, however, its large band gap could compromise carrier transfer. Herein, we synthesize a new molecule 2‐thiopheneethylamine thiocyanate (TEASCN) for the construction of bilayer quasi‐2D structure precisely on a tin‐lead mixed perovskite surface. This bilayer structure can passivate the perovskite surface and ensure effective carriers transfer simultaneously. As a result, the open‐circuit voltage ( V oc ) of the device is increased without sacrificing short‐circuit current density ( J sc ), giving rise to a high certified efficiency from a credible third‐party certification of narrow band gap perovskite solar cells. Furthermore, theoretical simulation indicates that the inclusion of TEASCN makes the bilayer structure thermodynamically more stable, which provides a strategy to tailor the number of layers of quasi‐2D perovskite structures. Abstract : TEASCN (2‐thiopheneethylamine thiocyanate) was synthesized to construct a bilayer structure on a Sn‐Pb perovskite surface, which can passivate perovskite and ensure effective carrier transfer, enabling the device to reach a certified efficiency of 21.1 %. The mechanism for the growth of the uniform bilayer structure is revealed by simulation based on density functional theory.