The evolution of 2D vdW ferroelectric materials: Theoretical prediction, experiment confirmation, applications

Since J. Valasek first discovered ferroelectric materials in 1920, researchers have been exploring continuously in various fields through theory and experiments. With the rapid development of the computing technology, energy efficiency and size requirements of semiconductor devices are becoming increasingly demanding. However, the conventional ferroelectric materials, which have been limited by physical size restrictions, can no longer satisfy the above requirements. Two-dimensional (2D) ferroelectric materials can effectively overcome the size limitation of traditional ferroelectrics due to the weak van der Waals force between layers, which is easy to thin while retaining their own unique properties. Currently, a small number of 2D materials have been proved to be ferroelectric properties by experiments and have shown great application potential in nanoscale electrical and optoelectronic devices, expected to become the leaders of next-generation computing. In this review, the current 2D ferroelectric materials are summarized and discussed in detail from seven aspects: theoretical prediction, fabrication methods, ferroelectric characterization methods, principles of typical 2D ferroelectrics, optimization methods of ferroelectric performance, application, and challenges. Finally, the development of 2D ferroelectric materials looks into the future.