Vapor Growth of All-Inorganic 2D Ruddlesden-Popper Lead- and Tin-Based Perovskites.

The 2D Ruddlesden-Popper (RP) perovskites CsPbICl (Pb-based, = 1) and CsSnICl (Sn-based, = 1) stand out as unique and rare instances of entirely inorganic constituents within the more expansive category of organic/inorganic 2D perovskites. These materials have recently garnered significant attention for their strong UV-light responsiveness, exceptional thermal stability, and theoretically predicted ultrahigh carrier mobility. In this study, we synthesized Pb and Sn-based = 1 2D RP perovskite films covering millimeter-scale areas for the first time, utilizing a one-step chemical vapor deposition (CVD) method under atmospheric conditions.

Two-dimensional perovskite templates for durable, efficient formamidinium perovskite solar cells.

We present a design strategy for fabricating ultrastable phase-pure films of formamidinium lead iodide (FAPbI) by lattice templating using specific two-dimensional (2D) perovskites with FA as the cage cation. When a pure FAPbI precursor solution is brought in contact with the 2D perovskite, the black phase forms preferentially at 100°C, much lower than the standard FAPbI annealing temperature of 150°C. X-ray diffraction and optical spectroscopy suggest that the resulting FAPbI film compresses slightly to acquire the (011) interplanar distances of the 2D perovskite seed.

Synergy of 3D and 2D Perovskites for Durable, Efficient Solar Cells and Beyond.

Three-dimensional (3D) organic-inorganic lead halide perovskites have emerged in the past few years as a promising material for low-cost, high-efficiency optoelectronic devices. Spurred by this recent interest, several subclasses of halide perovskites such as two-dimensional (2D) halide perovskites have begun to play a significant role in advancing the fundamental understanding of the structural, chemical, and physical properties of halide perovskites, which are technologically relevant. While the chemistry of these 2D materials is similar to that of the 3D halide perovskites, their layered structure with a hybrid organic-inorganic interface induces new emergent properties that can significantly or sometimes subtly be important.