Monolayered semiconducting GeAsSe and SnSbTe with ultrahigh hole mobility
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High carrier mobility and a direct semiconducting band gap are two key properties of materials for electronic device applications. Using first-principles calculations, we predict two types of two-dimensional semiconductors, ultrathin GeAsSe and SnSbTe nanosheets, with desirable electronic and optical properties. Both GeAsSe and SnSbTe sheets are energetically favorable, with formation energies of –0.19 and –0.09 eV/atom, respectively, and have excellent dynamical and thermal stability, as determined by phonon dispersion calculations and Born–Oppenheimer molecular dynamics simulations. The relatively weak interlayer binding energies suggest that these monolayer sheets can be easily exfoliated from the bulk crystals. Importantly, monolayer GeAsSe and SnSbTe possess direct band gaps (2.56 and 1.96 eV, respectively) and superior hole mobility (~ 20 000 cm2∙V–1∙s–1), and both exhibit notable absorption in the visible region. A comparison of the band edge positions with the redox potentials of water reveals that layered GeAsSe and SnSbTe are potential photocatalysts for water splitting. These exceptional properties make layered GeAsSe and SnSbTe promising candidates for use in future high-speed electronic and optoelectronic devices.
Keywords2D GeAsSe and SnSbTe carrier mobility photocatalysts DFT calculations
This work was supported by the National Natural Science Foundation of China (Grant No. 11574040), the Fundamental Research Funds for the Central Universities of China (Grant Nos. DUT16-LAB01 and DUT17LAB19). Y. G. was supported by China Scholarship Council (CSC, Grant No. 201706060138). X. C. Z. was supported by the National Science Foundation (NSF) through the Nebraska Materials Research Science and Engineering Center (MRSEC) (Grant No. DMR-1420645). We acknowledge the computing resource from the Supercomputing Center of Dalian University of Technology and the University of Nebraska Holland Computing Center.
- 18.D. A. Bandurin, A. V. Tyurnina, G. L. Yu, A. Mishchenko, V. Zólyomi, S. V. Morozov, R. K. Kumar, R. V. Gorbachev, Z. R. Kudrynskyi, S. Pezzini, Z. D. Kovalyuk, U. Zeitler, K. S. Novoselov, A. Patanè, L. Eaves, I. V. Grigorieva, V. I. Fal’ko, A. K. Geim, and Y. Cao, High electron mobility, quantum Hall effect and anomalous optical response in atomically thin InSe, Nat. Nanotechnol. 12(3), 223 (2017)ADSCrossRefGoogle Scholar
- 24.J. Wu, H. Yuan, M. Meng, C. Chen, Y. Sun, Z. Chen, W. Dang, C. Tan, Y. Liu, J. Yin, Y. Zhou, S. Huang, H. Q. Xu, Y. Cui, H. Y. Hwang, Z. Liu, Y. Chen, B. Yan, and H. Peng, High electron mobility and quantum oscillations in non-encapsulated ultrathin semiconducting Bi2O2Se, Nat. Nanotechnol. 12(6), 530 (2017)ADSCrossRefGoogle Scholar
- 30.N. Ashok, Y. L. Lee, and W. Shin, GeAsSe chalcogenide slot optical waveguide ring resonator for refractive index sensing, in: 2017 25th Optical Fiber Sensors Conference (OFS), 2017Google Scholar
- 41.L. A. Burns, Á. V. Mayagoitia, B. G. Sumpter, and C. D. Sherrill, Density-functional approaches to noncovalent interactions: A comparison of dispersion corrections (DFT-D), exchange-hole dipole moment (XDM) theory, and specialized functionals, J. Chem. Phys. 134(8), 084107 (2011)ADSCrossRefGoogle Scholar
- 58.W. Zhang, Y. G. Wang, Y. Ding, J. Yin, and P. Zhang, Two-dimensional GeAsSe with high and unidirectional conductivity, Nanoscale (2018)Google Scholar