A Family of Two-Dimensional Quaternary Compounds A2BXY2 (A = K, Na; B = Li, Na; X = Al, Ga, In; Y = P, As, Sb) for
Run-Jie Peng1, Ying Zhu1, Jun-Hui Yuan1
1Department of Physical Science and Technology, School of Physics and Mechanics, Wuhan University of Technology, Wuhan 430070, China.
Abstract:
Expanding material types and developing two-dimensional (2D) semiconductor materials with high performance have been hotspots in the field. In this research, it is found that the 12 existing semiconductors A2BXY2 (A = K, Na; B = Li, Na; X = Al, Ga, In; Y = P, As, Sb) have a pronounced layered structure. We predict their 2D structures and properties, using first-principles calculations. Lower exfoliation energies confirm the feasibility of mechanical exfoliation from their bulk phases and that the 2D structures can be stabilized independently at room temperature. Interestingly, A2BXY2 has an anionic tetrahedral one-dimensional chain or two-dimensional mesh structure of [XY2]3- composed of elements III-V. All A2BXY2 monolayers exhibit direct or indirect band gap features (0.78-1.94 eV). More encouragingly, the A2BXY2 monolayers possess ultrahigh carrier mobilities (∼105 cm2 V-1 s-1) at room temperature. Furthermore, the results based on the nonequilibrium Green's function indicate that 2D A2BXY2 exhibits a high ON/OFF ratio (∼104). To sum up, the A2BXY2 family is an outstanding promising candidate for optoelectronics application.
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