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

Nature Nanotechnology 12, 530 (2017). doi:10.1038/nnano.2017.43 Authors: Jinxiong Wu, Hongtao Yuan, Mengmeng Meng, Cheng Chen, Yan Sun, Zhuoyu Chen, Wenhui Dang, Congwei Tan, Yujing Liu, Jianbo Yin, Yubing Zhou, Shaoyun Huang, H. Q. Xu, Yi Cui, Harold Y. Hwang, Zhongfan Liu, Yulin Chen, Binghai Yan & Hailin Peng 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 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 deposition and at the LaAlO3–SrTiO3 interface, making the detection of Shubnikov–de Haas quantum oscillations possible. Top-gated field-effect tr...
Source: Nature Nanotechnology - Category: Nanotechnology Authors: Tags: Letter Source Type: research