Oriented lateral growth of two-dimensional materials on c-plane sapphire

Jui-Han Fu, Jiacheng Min, Che-Kang Chang, Chien-Chih Tseng, Qingxiao Wang, Hayato Sugisaki, Chenyang Li, Yu-Ming Chang, Ibrahim Alnami, Wei-Ren Syong, Ci Lin, Feier Fang, Lv Zhao, Tzu-Hsuan Lo, Chao-Sung Lai, Wei-Sheng Chiu, Zih-Siang Jian, Wen-Hao Chang, Yu-Jung Lu, Kaimin ShihLain-Jong Li, Yi Wan, Yumeng Shi, Vincent Tung

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

Two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs) represent the ultimate thickness for scaling down channel materials. They provide a tantalizing solution to push the limit of semiconductor technology nodes in the sub-1 nm range. One key challenge with 2D semiconducting TMD channel materials is to achieve large-scale batch growth on insulating substrates of single crystals with spatial homogeneity and compelling electrical properties. Recent studies have claimed the epitaxy growth of wafer-scale, single-crystal 2D TMDs on a c-plane sapphire substrate with deliberately engineered off-cut angles. It has been postulated that exposed step edges break the energy degeneracy of nucleation and thus drive the seamless stitching of mono-oriented flakes. Here we show that a more dominant factor should be considered: in particular, the interaction of 2D TMD grains with the exposed oxygen-aluminium atomic plane establishes an energy-minimized 2D TMD-sapphire configuration. Reconstructing the surfaces of c-plane sapphire substrates to only a single type of atomic plane (plane symmetry) already guarantees the single-crystal epitaxy of monolayer TMDs without the aid of step edges. Electrical results evidence the structural uniformity of the monolayers. Our findings elucidate a long-standing question that curbs the wafer-scale batch epitaxy of 2D TMD single crystals-an important step towards using 2D materials for future electronics. Experiments extended to perovskite materials also support the argument that the interaction with sapphire atomic surfaces is more dominant than step-edge docking.
Original languageEnglish (US)
JournalNature nanotechnology
DOIs
StatePublished - Jul 20 2023

ASJC Scopus subject areas

  • Biomedical Engineering
  • Bioengineering
  • General Materials Science
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering
  • Condensed Matter Physics

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