Recent Progress on Energy-Related Applications of HfO₂-Based Ferroelectric and Antiferroelectric Materials

Ferroelectric and antiferroelectric materials are promising options for energy-related (such as energy harvesting, energy storage, IR detection, and refrigeration) and memory applications (such as ferroelectric random-access memory (FeRAM) and ferroelectric field-effect transistor (FeFET)). In the past, several classes of materials (such as polymers, ceramics, single crystals, and glasses) have been studied for these properties. However, because of a large deposition thickness (in micrometers or larger), these materials are inappropriate for future nanoscale devices. Recently, the ferroelectric and antiferroelectric HfO2-based thin films have also been studied for the energy-related and memory applications. HfO2-based materials have many advantages over the conventional materials, such as compatibility with Si-based semiconductor technology, ultrasmall thicknesses (nm), and simple compositions, and they are appropriate for integration within 3-D nanostructures. HfO2-based materials can be promising for energy-related applications, such as energy storage, pyroelectric energy harvesting, IR sensors, and solid-state cooling. This article provides some basic knowledge of these energy-related properties. Moreover, this article reviews the energy-related properties of HfO2-based thin films, their origins, and the prospects of this research field.