Salt-Assisted Selective Growth of H-phase Monolayer VSe2 with Apparent Hole Transport Behavior

Authors：You, Jiawen; Pan, Jie; Shang, Shun-Li; Xu, Xiang; Liu, Zhenjing; Li, Jingwei; Liu, Hongwei; Kang, Ting; Xu, Mengyang; Li, Shaobo; Kong, Deqi; Wang, Wenliang^*; Gao, Zhaoli; Zhou, Xing; Zhai, Tianyou; Liu, Zi-Kui; Kim, Jang-Kyo; Luo, Zhengtang^*

Source：Nano Letters, 2022, 22(24): 10167-10175.

DOI：10.1021/acs.nanolett.2c04133

• VSe2
• 2D semiconductor
• Chemical vapor deposition
• Phase-selective growth

Vanadium diselenide (VSe2) exhibits versatile electronic and magnetic properties in the trigonal prismatic (H-) and octahedral (T-) phases. Compared to the metallic T-phase, the H-phase with a tunable semiconductor property is predicted to be a ferrovalley material with spontaneous valley polarization. Herein we report an epitaxial growth of the monolayer 2D VSe2 on a mica substrate via the chemical vapor deposition (CVD) method by introducing salt in the precursor. Our first-principles calculations suggest that the monolayer H-phase VSe2 with a large lateral size is thermodynamically favorable. The honeycomb-like structure and the broken symmetry are directly observed by spherical aberration-corrected scanning transmission electron microscopy (STEM) and confirmed by giant second harmonic generation (SHG) intensity. The p-type transport behavior is further evidenced by the temperature-dependent resistance and field-effect device study. The present work introduces a new phase-stable 2D transition metal dichalcogenide, opening the prospect of novel electronic and spintronics device design.

• Institution
  华中科技大学