High electron mobility and quantum oscillations in non-encapsulated ultrathin semiconducting Bi2O2Se

DOI: 10.1038/nnano.2017.43

Authors: Jinxiong Wu (Peking University) , Hongtao Yuan (Nanjing University) , Mengmeng Meng (Peking University) , Cheng Chen (University of Oxford) , Yan Sun (Max Planck Institute for Chemical Physics of Solids) , Zhuoyu Chen (Stanford University) , Wenhui Dang (Peking University) , Congwei Tan (Peking University) , Yujing Liu (Peking University) , Jianbo Yin (Peking University) , Yubing Zhou (Peking University) , Shaoyun Huang (Peking University) , H. Q. Xu (Peking University) , Yi Cui (SLAC National Accelerator Laboratory) , Harold Y. Hwang (SLAC National Accelerator Laboratory) , Zhongfan Liu (Peking University) , Yulin Chen (University of Oxford) , Binghai Yan (ShanghaiTech University) , Hailin Peng (Peking University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Nanotechnology , VOL 5

State: Published (Approved)
Published: April 2017
Diamond Proposal Number(s): 14132

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 research1, 2, 3, 4, 5, 6, 7, 8, 9. However, air-stable ultrathin semiconducting materials with superior performances remain elusive at present10. 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 cm2 V−1 s−1 is measured in as-grown Bi2O2Se nanoflakes at low temperatures. This value is comparable to what is observed in graphene grown by chemical vapour deposition11 and at the LaAlO3–SrTiO3 interface12, 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 cm2 V−1 s−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.

Journal Keywords: Two-dimensional materials

Diamond Keywords: Semiconductors

Subject Areas: Materials, Physics


Instruments: I05-ARPES

Added On: 30/05/2017 11:17

Discipline Tags:

Surfaces Quantum Materials Physics Hard condensed matter - structures Electronics Materials Science interfaces and thin films

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)