First-principles study of phase transition in the α-In2Se3/metal heterostructures

Abstract With the discovery of two-dimensional (2D) ferroelectric materials such as CuInP 2 S 6 and α -In 2 Se 3 , the ferroelectric field effect transistors (Fe-FETs) based on these materials have entered a rapid-development period. The metal/semiconductor contact is an unavoidable topic in the construction of devices. In this paper, heterostructures α -In 2 Se 3 /metals (Pd, Pt, Cu, Ag and Au) are discussed. According to different stacking types, the structures and energy of 160 heterostructures are calculated and compared. When α -In 2 Se 3 contacts with the Pd, Pt and Cu, the α -In 2 Se 3 may transforms into β -In 2 Se 3 . This phenomenon has hardly been mentioned or analyzed in previous reports. Contacting with the Au and Ag, the α -In 2 Se 3 maintains the original structure. The internal physical mechanism of phase transition is explained from the binding energy and the charge transfer. The paper provides sufficient theoretical support for research and development of the Fe-FETs based on α -In 2 Se 3 .