Emerging Molecular Antiferroelectrics: Advances and Prospects.

Antiferroelectrics (AFEs) with typical reversible electrically antipolar-polar phase transformation have attracted tremendous attention for assembling electronic devices. As a thriving part of the family, molecular antiferroelectrics, referring to the crystalline assembly of organic molecules and organic-inorganic hybrids, have emerged due to their diverse structures, facile synthesis, and intriguing antiferroelectricity. Especially, the polarization switch of molecular AFEs involves the weak interactions; thus, lower switching energy barriers and smaller required electric fields are expected in such soft materials, which manifest significant application potential in highly efficient and low-consumption electronics applications. This review focuses on the current research progress in molecular antiferroelectrics, encompassing their diverse structures, antiferroelectricity-associated properties, and application exploration, including energy storage, electrocaloric refrigeration, and electrostriction. Moreover, we discuss the current challenges and future opportunities in this exciting field. With the breaking of traditional inorganic systems, molecular AFEs provide a broad and versatile platform for boosting the multifunctionality of AFEs.