Wafer-scale growth of two-dimensional, phase-pure InSe

Two-dimensional (2D) indium monoselenide (InSe) has attracted significant attention as an ultrathin III–VI semiconductor with a combination of favorable attributes that are comparable to those III–V semiconductors and van der Waals 2D transition-metal dichalcogenides. Nevertheless, there been no demonstration large-area synthesis InSe due the complexity binary In-Se system difficulties in promoting lateral growth. Here, we report polymorph-selective epitaxial by metal-organic chemical vapor deposition (MOCVD) over 2-in wafers. We achieve growth on c-plane sapphire via flow modulation control Se/In ratio. The layer-by-layer allows thickness tunable optical properties bulk crystals. also demonstrate gate-tunable electrical transport field-effect mobility single-crystalline flakes. These results indicate grown MOCVD could be effective channel material for back-end-of-line integration logic transistors.