<br/><br/>Ruddlesden-Popper perovskites are layered two-dimensional materials with alternating organic and inorganic layers that are promising for many optoelectronic devices, such as LEDs, nanoscale lasers, and solar cells. Yet, these materials are highly dynamic and often exhibit structural transformations at relatively low temperatures. Harnessing these structural transformations represents a significant opportunity for switchable technologies, such as smart windows and memory applications. These transformations, however, may also lead to degradation. Using pentylammonium lead iodide ((PA)2PbI4) thin films as a model system, we probe the order-to-disorder phase transition of the pentylammonium cations as a function of temperature using grazing incidence wide angle X-ray scattering (GIWAXS) and photoluminescence (PL) spectroscopy. Using PL microscopy with in situ heating, we also visualize this structural transformation and find that the dynamics of melting and freezing of the organic layer are very different. Last, we show that cation alloying can suppress structural phase transitions in 2D perovskites. Controlling phase transitions in 2D perovskites may lead to new opportunities for thermal energy storage and switchable optoelectronics.

Probing and controlling structural phase transitions in 2D Ruddlesden-Popper perovskites

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.