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

2023; Elsevier BV; Volume: 6; Issue: 10 Linguagem: Inglês

10.1016/j.matt.2023.07.012

2590-2393

Seunguk Song, Seil Jeon, Mahfujur Rahaman, Jason Lynch, Dongjoon Rhee, Pawan Kumar, Srikrishna Chakravarthi, Gwangwoo Kim, Xingyu Du, Eric W. Blanton, Kim Kisslinger, Michael Snure, Nicholas R. Glavin, Eric A. Stach, Roy H. Olsson, Deep Jariwala,

Phase-change materials and chalcogenides

Progress and potentialTwo-dimensional (2D) InSe has attracted attention for next-generation electronic devices due to its atomically thin structure with a low effective mass and high thermal velocity among known 2D semiconductors. However, scalable synthesis of high-quality InSe with high phase purity remains unachieved. This study introduces a pulsed-precursor, metal-organic chemical vapor deposition technique for the epitaxial synthesis of InSe on c-plane sapphire. Pulsing precursors during the synthesis process effectively controls the In-to-Se ratio, thereby widening the growth window for pure InSe instead of In2Se3. The resulting high-quality InSe demonstrates promising optical and electrical properties. This highlights the potential of our synthesis technique for achieving future high-performance optoelectronic materials, including various 2D III–VI compound semiconductors at temperatures below 500°C.Highlights•First polymorph-selective epitaxy of 2D InSe thin film is demonstrated•Flow-modulation technique enables selective nucleation of InSe instead of In2Se3•Layer-by-layer growth mode enables production of InSe with different thicknesses•As-grown InSe shows electronic and optical properties similar to exfoliated flakesSummaryTwo-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 of III–V semiconductors and van der Waals 2D transition-metal dichalcogenides. Nevertheless, there has been no demonstration of large-area synthesis of 2D InSe due to the complexity of the binary In-Se system and the difficulties in promoting lateral growth. Here, we report the polymorph-selective synthesis of epitaxial 2D InSe by metal-organic chemical vapor deposition (MOCVD) over 2-in wafers. We achieve polymorph-selective epitaxial growth of InSe on c-plane sapphire via flow modulation to control the Se/In ratio. The layer-by-layer growth allows thickness control with tunable optical properties comparable to those of bulk crystals. We also demonstrate gate-tunable electrical transport with a field-effect mobility comparable to that of single-crystalline flakes. These results indicate that InSe grown by MOCVD could be an effective channel material for back-end-of-line integration in logic transistors.Graphical abstract