Epitaxial growth of few-layer β-In2Se3 thin films by metalorganic chemical vapor deposition

Recent interest in the family of layered indium selenides has grown rapidly due to their intriguing properties such as photoresponsivity and ferroelectricity. However, practical applications require uniform crystalline films over large area. Here we report epitaxial growth of layered beta-In2Se3 thin films by metalorganic chemical vapor deposition (MOCVD) using trimethyl indium (TMIn) and H2Se in a hydrogen ambient. Epitaxy has been realized on both c-plane sapphire and Si (1 1 1) while different growth modes were observed on these two substrates. Few-layer beta-In2Se3 films have been successfully achieved by precursor pulsing to minimize gas phase pre-reactions. Finally, top gate beta-In2Se3 thin film transistors with field effect mobility near 1 cm(2)/V.s have been demonstrated. This work offers a scalable production of high-quality beta-In2Se3 films and potential integration with 3D fabrication and flexible electronics under low processing temperature.