Room Temperature Electrocaloric Effect in Layered Ferroelectric CuInP2S6 for Solid State Refrigeration

TL;DR

This study demonstrates significant electrocaloric effects in layered ferroelectric CuInP2S6 at near room temperature, showing promise for solid-state cooling applications with high efficiency and reversible temperature change.

Contribution

It reports the first detailed experimental and theoretical investigation of electrocaloric effects in CuInP2S6, a layered ferroelectric material, highlighting its high performance near room temperature.

Findings

Achieved 3.3 K adiabatic temperature change at 315 K.

Observed over 60% polarization charge change within 10 K.

Demonstrated large electrocaloric strength of 29.5 mK cm kV-1.

Abstract

A material with reversible temperature change capability under an external electric field, known as the electrocaloric effect (ECE), has long been considered as a promising solid-state cooling solution. However, electrocaloric (EC) performance of EC materials generally is not sufficiently high for real cooling applications. As a result, exploring EC materials with high performance is of great interest and importance. Here, we report on the ECE of ferroelectric materials with van der Waals layered structure (CuInP2S6 or CIPS in this work in particular). Over 60% polarization charge change is observed within a temperature change of only 10 K at Curie temperature. Large adiabatic temperature change (|{\Delta}T|) of 3.3 K, isothermal entropy change (|{\Delta}S|) of 5.8 J kg-1 K-1 at |{\Delta}E|=142.0 kV cm-1 at 315 K (above and near room temperature) are achieved, with a large EC strength (|{\Delta}T|/|{\Delta}E|) of 29.5 mK cm kV-1. The ECE of CIPS is also investigated theoretically by numerical simulation and a further EC performance projection is provided.