Orbital Interactions between the Organic Semiconductor Spacer and the Inorganic Layer in Dion–Jacobson Perovskites Enable Efficient Solar Cells. Issue 3 (15th December 2022)

• Record Type: Journal Article
• Authors: Dong, Yixin; Dong, Xiyue; Lu, Di; Chen, Mingqian; Zheng, Nan; Wang, Rui; Li, Qiaohui; Xie, Zengqi; Liu, Yongsheng
• Is Part Of: Advanced materials. Volume 35:Issue 3(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-15
• Subjects: 2D perovskites -- charge transport -- Dion–Jacobson perovskites -- organic semiconductor spacers -- solar cells; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202205258
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: 2D Dion–Jacobson (DJ) perovskites have become emerging photovoltaic materials owing to their intrinsic structure stability. However, as insulating aliphatic cations are widely used as spacers, the interactions between the spacers and inorganic layers in DJ perovskites have rarely been studied. Here, an organic semiconductor spacer with two covalently connected thiophene rings, namely bithiophene dimethylammonium (BThDMA), is successfully developed for 2D DJ perovskite solar cells (PSCs). An important finding is that there are strong orbital interactions between the conjugated organic spacer and adjacent inorganic layers, whereas no such interactions exist in DJ perovskite using an aliphatic octane‐1, 8‐diaminium (ODA) spacer with similar length. The BThDMA spacer with multiple conjugated aromatic rings can also induce crystal growth with large grain size and preferred vertical orientation, resulting in reduced trap density and improved charge‐carrier mobility. As a result, the optimized device based on (BThDMA)MA n −1 Pb n I3 n +1 (nominal n = 5) shows an excellent PCE of 18.1% with negligible hysteresis, which is a record efficiency for 2D DJ PSCs using a spacer with two or more covalently linked aromatic rings. These findings provide a novel and important insight on achieving efficient and stable 2D DJ perovskite solar cells by developing organic semiconductor spacers. Abstract : A semiconductor spacer, namely bithiophenedimethylamine (BThDMA), is successfully developed for 2D Dion–Jacobson (DJ) perovskite solar cells (PSCs) and high photovoltaic performance is demonstrated. An important finding is that there are strong orbital interactions between the conjugated organic spacer and the adjacent inorganic layers, whereas no such interactions exist in DJ perovskites using an insulating aliphatic spacer with similar length.