skip to main content


Title: High electron mobility and quantum oscillations in non-encapsulated ultrathin semiconducting Bi 2O 2Se

Identifying new two-dimensional (2D) materials with both high carrier mobility and a large electronic band gap is critical for novel electronics and optoelectronics applications. Here, we demonstrated a new air-stable ultrahigh-mobility layered Bi 2O 2Se semiconductor with a large band gap of ~ 0.8 eV and a low effective mass of ~ 0.14 m 0. High-quality 2D Bi2O2Se crystals with a thickness down to a monolayer and a domain size greater than 200 μm were readily grown by chemical vapor deposition (CVD). Size-tunable band gap of Bi 2O 2Se was found to increase as thinning down to the monolayer due to the quantum confinement effect. An ultrahigh Hall mobility of > 20,000 cm 2 V -1 s -1 was achieved in as-grown Bi 2O 2Se flakes at 1.9 K, which allows for the observation of Shubnikov–de Haas quantum oscillations. Top-gated field-effect transistors based on CVD-grown 2D Bi 2O 2Se crystals (down to bilayer) exhibited high Hall mobility (up to 450 cm 2 V -1 s -1), large current on/off ratios (>106) and near-ideal subthreshold swings (~65 mV/dec) at room temperature. Our results make the high-mobility 2D Bi 2O 2Se semiconductor a promising candidate for future high-speed and low-power electronic applications.
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ; ORCiD logo [6] ;  [1] ;  [1] ;  [1] ; ORCiD logo [1] ;  [1] ; ORCiD logo [3] ;  [3] ;  [2] ;  [2] ;  [1] ;  [4] ; ORCiD logo [5] ;  [1]
  1. Peking Univ., Beijing (China). Center for Nanochemistry, Beijing National Lab. for Molecular Sciences (BNLMS)
  2. Stanford Univ., CA (United States). Geballe Lab. for Advanced Materials; SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES)
  3. Peking Univ., Beijing (China). State Key Lab. for the Physics and Chemistry of Nanodevices
  4. Univ. of Oxford (United Kingdom). Dept. of Physics and Clarendon Lab.
  5. Max Planck Inst. for Chemical Physics of Solids, Dresden (Germany); ShanghaiTech Univ. (China). School of Physical Science and Technology
  6. Stanford Univ., CA (United States). Geballe Lab. for Advanced Materials
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Nature Nanotechnology
Additional Journal Information:
Journal Volume: 12; Journal Issue: 3; Journal ID: ISSN 1748-3387
Nature Publishing Group
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
Country of Publication:
United States
36 MATERIALS SCIENCE; electronic devices; electronic properties and devices; two-dimensional materials
OSTI Identifier: