Prediction of intrinsic two-dimensional ferroelectrics in In2Se3 and other III2-VI3 van der Waals materials

• Published in: Nature communications Vol. 8; no. 1; pp. 14956 - 8
• Main Authors: Ding, Wenjun, Zhu, Jianbao, Wang, Zhe, Gao, Yanfei, Xiao, Di, Gu, Yi, Zhang, Zhenyu, Zhu, Wenguang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 07.04.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 639/301/357/1018; 639/766/119/996; Ferroelectrics; Humanities and Social Sciences; MATERIALS SCIENCE; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms14956

Interest in two-dimensional (2D) van der Waals materials has grown rapidly across multiple scientific and engineering disciplines in recent years. However, ferroelectricity, the presence of a spontaneous electric polarization, which is important in many practical applications, has rarely been reported in such materials so far. Here we employ first-principles calculations to discover a branch of the 2D materials family, based on In 2 Se 3 and other III 2 -VI 3 van der Waals materials, that exhibits room-temperature ferroelectricity with reversible spontaneous electric polarization in both out-of-plane and in-plane orientations. The device potential of these 2D ferroelectric materials is further demonstrated using the examples of van der Waals heterostructures of In 2 Se 3 /graphene, exhibiting a tunable Schottky barrier, and In 2 Se 3 /WSe 2 , showing a significant band gap reduction in the combined system. These findings promise to substantially broaden the tunability of van der Waals heterostructures for a wide range of applications. The development of devices based on 2D materials beyond graphene benefits from identifying compounds with diverse functional properties. Here, the authors predict computationally that 2D In 2 Se 3 and related materials are room temperature ferroelectrics with both in- and out-of-plane polarization.