Vapor-Deposited n = 2 Ruddlesden–Popper Interface Layers Aid Charge Carrier Extraction in Perovskite Solar Cells

作者：Carlo A. R. Perini, Andrés‐Felipe Castro‐Mendez, Tim Kodalle, Magdalena Ravello, Juanita Hidalgo, Martin Gómez-Domínguez, Ruipeng Li, Margherita Taddei, Rajiv Giridharagopal, Justin Pothoof, Carolin M. Sutter‐Fella, David S. Ginger, Juan‐Pablo Correa‐Baena · 发表于：ACS Energy Letters · 年份：2023 · DOI：10.1021/acsenergylett.2c02419 · 被引用次数：40 · 研究领域：Perovskite Materials and Applications、Chalcogenide Semiconductor Thin Films、Quantum Dots Synthesis And Properties

Interfacial passivation with bulky organic cations such as phenetylammonium iodide has enabled high performance for metal halide perovskite optoelectronic devices. However, the homogeneity of these interfaces and their formation dynamics are poorly understood. We study how Ruddlesden–Popper 2D phases form at a 3D perovskite interface when the 2D precursors are introduced via solution or via vapor. When using vapor deposition, we observe uniform coverage of the capping layer and the formation of a predominantly n = 2 Ruddlesden–Popper phase. In contrast, when using solution deposition, we observe the presence of a mixture of n = 2 and n = 1 in the film and the formation of aggregates of the organic cations. As a result of the better phase purity and uniformity, vapor deposition enables higher median solar cell performance with narrower distribution compared to solution-treated films. This study provides fundamental information that the perovskite community can use to better design capping layers to achieve higher charge extraction efficiencies.