Organic–inorganic Pb-free layered perovskites
are efficient
broadband emitters and thus are promising materials for lighting applications.
However, their synthetic protocols require a controlled atmosphere,
high temperature, and long preparation time. This hinders the potential
tunability of their emission through organic cations, as is instead
common practice in Pb-based structures. Here, we present a set of
Sn–Br layered perovskite-related structures that display different
chromaticity coordinates and photoluminescence quantum yield (PLQY)
up to 80%, depending on the choice of the organic monocation. We first
develop a synthetic protocol that is performed under air and at 4
°C, requiring only a few steps. X-ray and 3D electron diffraction
analyses show that the structures exhibit diverse octahedra connectivity
(disconnected and face-sharing) and thus optical properties, while
preserving the organic–inorganic layer intercalation. These
results provide key insight into a previously underexplored strategy
to tune the color coordinates of Pb-free layered perovskites through
organic cations with complex molecular configurations.