Correlating Structural Phase Transitions and Optoelectronic Properties in Two-Dimensional Perovskites

Ruddlesden-Popper (RP) metal halide perovskites have emerged as a promising class of optoelectronic materials. Due to their two-dimensional (2D) structure of alternating layers of organic cations and metal halide octahedra, these materials can undergo structural phase transitions near room temperature that drastically affect their optical properties. And yet, the connection between the structural dynamics of these materials and their optoelectronic properties have not been extensively studied. As such, this work aims to correlate changes in optoelectronic properties to subtle structural changes in the 2D perovskite lattice using photoluminescence (PL) spectroscopy and temperature-dependent grazing incidence wide angle X-ray scattering (GIWAXS), respectively. Additionally, we visualize the dynamics of 2D perovskite phase transitions using PL microscopy and find that the phase transition dynamics depend on the identity of the organic cation.