Recent advances of phase transition and ferroelectric device in two-dimensional In2Se3

The coupling of ferroelectric, photoelectric, semiconducting, and phase transition properties make two-dimensional (2D) In2Se3 a material platform with great application potential in the phase change memory, intelligent sensing, and in-memory computing devices. However, at present, there are unclear phase transition mechanisms and ferroelectric dynamics in 2D In2Se3, which seriously hinder the development of device applications. In this review, we mainly highlight the phase transition mechanisms and ferroelectric devices of In2Se3 beginning with the history of bulk In2Se3 and of 2D In2Se3. The phase transition relations of the four In2Se3 phases, including α-, β-, β′-, and γ-phases, under various driving forces, are summarized. The different driving forces, including temperature, laser, electric-field, vacancy, doping, and strain, are introduced and discussed. Moreover, the phase-control growth of 2D In2Se3 films and their novel ferroelectric device applications are demonstrated. Finally, a perspective on future research directions of 2D In2Se3 is provided.