Invited for this month's cover are collaborators from University of Pavia, École Polytechnique Fédérale de Lausanne, University of Messina and Istituto Italiano di Tecnologia. The cover picture shows the crystal structure of a Ruddlesden-Popper quasi-2D perovskite with chemical formula (PEA)₂MA₃₉Pb₄₀I₁₂₁ (with PEA: phenylethylammonium and MA: methylammonium). The subscript 40 indicates the number of PbI₆ octahedra separated by a double layer of PEA cations. Such quasi-2D perovskites exhibit efficient photovoltaic performances and higher stability with respect to the pure 3D counterpart (MAPbI₃). This article is part of the Special Collection on “Perovskite Materials and Devices”. Read the full text of the article at 10.1002/cplu.202000777.

中文翻译：

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两步热退火：效率为 15% 的准二维钙钛矿太阳能电池的有效途径

本月的封面邀请来自帕维亚大学、洛桑联邦理工学院、墨西拿大学和意大利理工学院的合作者。封面图片显示了 Ruddlesden-Popper 准二维钙钛矿的晶体结构，其化学式为 (PEA) ₂ MA ₃₉ Pb ₄₀ I ₁₂₁（PEA：苯乙基铵，MA：甲基铵）。下标 40 表示被双层 PEA 阳离子隔开的 PbI ₆八面体的数量。这种准 2D 钙钛矿相对于纯 3D 对应物（MAPbI ₃）。本文是“钙钛矿材料和器件”特别收藏的一部分。在10.1002/clu.202000777阅读文章全文。