Phonon and electronic properties of semiconducting silicon nitride bilayers

Jiesen Li; Wanxing Lin; Junjun Shi; Feng Zhu; Haiwen Xie; Dao-Xin Yao

doi:10.1016/j.physleta.2024.129457

paper

Phonon and electronic properties of semiconducting silicon nitride bilayers

arXiv:1707.02819 · doi:10.1016/j.physleta.2024.129457

Abstract

The two-dimensional (2D) IV-V semiconductors have attracted much attention due to their fascinating electronic and optical properties. In this work, we predicted three phases of silicon nitrides, denoted $α$ -Si $_{2}$ N $_{2}$ , $β$ -Si $_{2}$ N $_{2}$ , and $γ$ -Si $_{4}$ N $_{4}$ , respectively. Both $α$ -Si $_{2}$ N $_{2}$ and $β$ -Si $_{2}$ N $_{2}$ consist of two buckled SiN sheets, and $γ$ -Si $_{4}$ N $_{4}$ consists of two puckered SiN sheets. It is challenging to transform between $α$ -Si $_{2}$ N $_{2}$ and $β$ -Si $_{2}$ N $_{2}$ because of the high energy barrier. The three dynamically stable bilayers are semiconductors with fundamental indirect band gaps from 0.25 eV to 2.92 eV. As expected, only the s and p orbitals contribute to the electronic states, and the pz orbitals dominate near the Fermi level. Furthermore, insulator-metal transitions occur in $α$ -Si $_{2}$ N $_{2}$ and $β$ -Si $_{2}$ N $_{2}$ under the biaxial strain of 16%. These materials perhaps have potential applications in microelectronics and spintronics.

22 pages, 15 figures