Controllable growth α-In2Se3 flakes by chemical vapor deposition

Boosting large-scale application of two-dimensional ferroelectric materials as memory transistors has stimulated intensive research interest. Layered α-In2Se3 features strikingly ferroelectric properties, which allows unique opportunities for the engineering of functional ferroelectric devices. However, the large-scale and controllable growth of the α-In2Se3 has remained a challenge due to the complexity of indium-selenium growth phase diagram. Here, we report the controllable growth of α-In2Se3 flakes using the developed confined-space modulated chemical vapor deposition (CVD) method. The α-In2Se3 flakes are preferred to be deposited on the inner surfaces of the confined space while the β-In2Se3 flakes are mainly grown on the outer surfaces of the confined space. In addition, the grown α-In2Se3 flake possesses a large size of ∼ 60 μm, uniform thickness of ∼ 2.8 nm and distinct ferroelectric properties. Our findings offer an effective and easily accessible method for controllable growth of two-dimensional layered materials and hold promise for further insight into the fascinating physical properties and potential practical devices applications of van der Waal crystals.