One-Step Synthesis of Two-Dimensional Metal–Semiconductor Circuitry Based on W‑Triggered Spatial Phase Engineering

• Published in: ACS materials letters 2023-09, Vol.5 (9), p.2324-2331
• Main Authors: Zeng, Yi, Wu, Shengqiang, Xu, Xiaolong, Zhang, Biao, Han, Bo, Zhao, Zijing, Pan, Yu, Wang, Feng, Wang, Qi, Ran, Yuqia, Gao, Peng, Zhao, Xiaoxu, Ye, Yu, Hou, Yanglong
• Format: Article
• Language: English
• ISSN: 2639-4979; 2639-4979
• DOI: 10.1021/acsmaterialslett.3c00654

Molybdenum ditelluride (MoTe2) exhibits a variety of crystal phases, which can be phase-controlled by various external means, showing broad prospects in modern integrated circuits. The structure in which the semimetal 1T′ (or Td) phase electrode contacts the semiconductor 2H phase channel is considered an elegant solution for high-performance two-dimensional (2D) circuits because it achieves low contact resistance. However, most of the 2D metal–semiconductor structures for large-area integration use a two-step growth process, which puts forward high requirements for the secondary growth compatibility of the material. Here, we develop a method for the stable synthesis of the metallic Mo x W1–x Te2 (0 < x < 1) by W-triggered spatial phase engineering, and we further obtain a large-area Mo x W1–x Te2/2H-MoTe2 in-plane metal–semiconductor structure by one-step tellurization of a MoW/Mo periodic structure. Due to the unique 2D in-plane epitaxial mechanism of the phase transition from 1T′ to 2H, the highly crystalline semiconductor 2H-MoTe2 squeezes between two metallic Mo x W1–x Te2 electrodes and forms a seamless coplanar contacted channel; thus, the fabricated field-effect transistors exhibit good electrical characteristics. In addition, large-area 2D metal–semiconductor heterostructure arrays can be transferred onto flexible substrates, showing promising applications in flexible electronics. Herein, one-step synthesis of large-area 2D in-plane metal–semiconductor arrays opens up new possibilities for future integrated high-performance logic circuits.