Colossal barocaloric effects with ultralow hysteresis in two-dimensional metal-halide perovskites

Jinyoung Seo; Ryan D McGillicuddy; Adam H Slavney; Selena Zhang; Rahil Ukani; Andrey A Yakovenko; Shao-Liang Zheng; Jarad A Mason

doi:10.1038/s41467-022-29800-9

Colossal barocaloric effects with ultralow hysteresis in two-dimensional metal-halide perovskites

Nat Commun. 2022 May 9;13(1):2536. doi: 10.1038/s41467-022-29800-9.

Authors

Jinyoung Seo¹, Ryan D McGillicuddy¹, Adam H Slavney¹, Selena Zhang¹, Rahil Ukani¹, Andrey A Yakovenko², Shao-Liang Zheng¹, Jarad A Mason³

Affiliations

¹ Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA.
² X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA.
³ Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA. mason@chemistry.harvard.edu.

Abstract

Pressure-induced thermal changes in solids-barocaloric effects-can be used to drive cooling cycles that offer a promising alternative to traditional vapor-compression technologies. Efficient barocaloric cooling requires materials that undergo reversible phase transitions with large entropy changes, high sensitivity to hydrostatic pressure, and minimal hysteresis, the combination of which has been challenging to achieve in existing barocaloric materials. Here, we report a new mechanism for achieving colossal barocaloric effects that leverages the large volume and conformational entropy changes of hydrocarbon order-disorder transitions within the organic bilayers of select two-dimensional metal-halide perovskites. Significantly, we show how the confined nature of these order-disorder phase transitions and the synthetic tunability of layered perovskites can be leveraged to reduce phase transition hysteresis through careful control over the inorganic-organic interface. The combination of ultralow hysteresis and high pressure sensitivity leads to colossal reversible isothermal entropy changes (>200 J kg^-1 K^-1) at record-low pressures (<300 bar).