Two-dimensional alkali auride bimetallene semiconductors

• Published in: Science China materials Vol. 67; no. 4; pp. 1209 - 1216
• Main Authors: Zhang, Kai, Lv, Haifeng, Wu, Xiaojun, Yang, Jinlong
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01-04-2024; Springer Nature B.V
• Subjects: Alkali metal alloys; Alloying elements; Atomic structure; Bimetals; Chemistry and Materials Science; Chemistry/Food Science; Crystal lattices; Electronegativity; Energy gap; First principles; Gold; Ionic crystals; Materials Science; Molecular dynamics; Nanoelectronics; Room temperature; Semiconductors; Two dimensional materials; first-principles; bimetallene; semiconductor; ionic bond
• ISSN: 2095-8226; 2199-4501
• DOI: 10.1007/s40843-023-2818-6

Alloying different metal elements to form two-dimensional (2D) materials (metallenes) holds great significance for both fundamental research and practical applications in nanoelectronics, but few of them are semiconductors with intrinsic band gaps. Here, inspired by bond characteristics in ionic crystals, we report a family of lattice dynamically stable 2D alkali auride bimetallene semiconductors with ionic bonding between alkali and gold atoms by extensive structure search and bonding analysis
via
high-throughput first-principles calculations over 2500 bimetallenes. Among them, 32 2D alkali auride bimetallenes are semiconductors with large band gaps ranging from 0.97 to 5.20 eV due to the large difference in electronegativity between alkali and gold atoms. Exceptionally, 2D LiAu bimetallene is metallic due to the reduced electronegativity difference between Li and Au atoms. Born-Oppenheimer molecular dynamic simulations imply that 19 alkali auride bimetallenes are structurally stable at room temperature for practical applications. This study provides guidance for designing bimetallene semiconductors and deepens the understanding of the correlation between the bonding behavior and electronic properties of 2D metal alloys.