Thermal and Humidity Stability of Mixed Spacer Cations 2D Perovskite Solar Cells. Issue 12 (6th May 2021)

• Record Type: Journal Article
• Authors: Yu, Huayang; Xie, Yulin; Zhang, Jia; Duan, Jiashun; Chen, Xu; Liang, Yudong; Wang, Kai; Xu, Ling
• Is Part Of: Advanced science. Volume 8:Issue 12(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-06
• Subjects: 2D perovskites -- orientation -- quantum wells distribution, solar cells -- spacer cations -- stability; Science -- Periodicals; 505
• DOI: 10.1002/advs.202004510
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: In this article, two different types of spacer cations, 1, 4‐butanediamonium (BDA 2+ ) and 2‐phenylethylammonium (PEA + ) are co‐used to prepare the perovskite precursor solutions with the formula of (BDA)1‐ a (PEA2 ) a MA4 Pb5 X16 . By simply mixing the two spacer cations, the self‐assembled polycrystalline films of (BDA)0.8 (PEA2 )0.2 MA4 Pb5 X16 are obtained, and BDA 2+ is located in the crystal grains and PEA + is distributed on the surface. The films display a small exciton binding energy, uniformly distributed quantum wells and improved carrier transport. Besides, utilizing mixed spacer cations also induces better crystallinity and vertical orientation of 2D perovskite (BDA)0.8 (PEA2 )0.2 MA4 Pb5 X16 films. Thus, a power conversion efficiency (PCE) of 17.21% is achieved in the optimized perovskite solar cells with the device structure of ITO/PEDOT:PSS/Perovskite/PCBM/BCP/Ag. In addition, the complementary humidity and thermal stability are obtained, which are ascribed to the enhanced interlayer interaction by BDA 2+ and improved moisture resistance by the hydrophobic group of PEA + . The encapsulated devices are retained over 95% or 75% of the initial efficiency after storing 500 h in ambient air under 40 ± 5% relative humidity or 100 h in nitrogen at 60 °C. Abstract : In this work, the mixed spacer cations 2D perovskite (BDA)0.8 (PEA2 )0.2 MA4 Pb5 X16 films are obtained by employing two typical spacer cations, 1, 4‐butanediamonium (BDA 2+ ) usually for Dion‐Jacobson phase and 2‐phenylethylammonium (PEA + ) for Ruddlesden‐Popper phase. The device with (BDA)0.8 (PEA2 )0.2 MA4 Pb5 X16 film achieves the power conversion efficiency of 17.21% with excellent thermal and humidity stability.