title: High electron mobility and quantum oscillations in non-encapsulated ultrathin semiconducting Bi2O2Se.
abstract: High-mobility semiconducting ultrathin films form the basis of modern electronics, and may lead to the scalable fabrication of highly performing devices. Because the ultrathin limit cannot be reached for traditional semiconductors, identifying new two-dimensional materials with both high carrier mobility and a large electronic bandgap is a pivotal goal of fundamental research. However, air-stable ultrathin semiconducting materials with superior performances remain elusive at present. Here, we report ultrathin films of non-encapsulated layered Bi2O2Se, grown by chemical vapour deposition, which demonstrate excellent air stability and high-mobility semiconducting behaviour. We observe bandgap values of ∼0.8 eV, which are strongly dependent on the film thickness due to quantum-confinement effects. An ultrahigh Hall mobility value of >20,000 cm2V-1s-1is measured in as-grown Bi2O2Se nanoflakes at low temperatures. This value is comparable to what is observed in graphene grown by chemical vapour deposition and at the LaAlO3-SrTiO3interface, making the detection of Shubnikov-de Haas quantum oscillations possible. Top-gated field-effect transistors based on Bi2O2Se crystals down to the bilayer limit exhibit high Hall mobility values (up to 450 cm2V-1s-1), large current on/off ratios (>106) and near-ideal subthreshold swing values (∼65 mV dec-1) at room temperature. Our results make Bi2O2Se a promising candidate for future high-speed and low-power electronic applications.
authors.affiliation: Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Jinxiong
authors.initials: J
authors.lastname: Wu
authors.affiliation: National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.|Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA.|Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Yuan
authors.affiliation: Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Meng
authors.affiliation: Department of Physics and Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK.
authors.forename: Cheng
authors.initials: C
authors.lastname: Chen
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.|School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA.
authors.forename: Zhuoyu
authors.identifier: 0000-0002-6111-7558
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Dang
authors.affiliation: Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Congwei
authors.initials: C
authors.lastname: Tan
authors.affiliation: Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Yujing
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Jianbo
authors.identifier: 0000-0001-6610-3916
authors.initials: J
authors.lastname: Yin
authors.affiliation: Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Yubing
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China.
authors.forename: Shaoyun
authors.identifier: 0000-0002-2222-3999
authors.initials: S
authors.lastname: Huang
authors.affiliation: Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China.
authors.forename: H Q
authors.initials: HQ
authors.lastname: Xu
authors.affiliation: Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA.|Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA.|Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors.forename: Harold Y
authors.initials: HY
authors.lastname: Hwang
authors.affiliation: Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Zhongfan
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Physics and Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.|School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China.
authors.forename: Binghai
authors.identifier: 0000-0003-2164-5839
authors.initials: B
authors.lastname: Yan
authors.affiliation: Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Hailin
authors.initials: H
authors.lastname: Peng