On July 24, the research groups led by Researcher Zheng Wang and Associate Professor Xiaoguang Li from the Institute for Advanced Study at Shenzhen University published a research paper titled “Phase-dependent electronic, optical, and phonon transport properties in ZrSi₂N₄ monolayers” in the internationally renowned physics journal Physical Review B (Phys. Rev. B 112, 014112, 2025). This study systematically reveals the differences in the electronic structure, optical response, and thermal transport properties of ZrSi₂N₄ monolayers in two different crystalline phases (2H and 1T), providing important theoretical guidance for the design of novel optoelectronic devices and thermal management materials.
Using density functional theory, the research team carried out a systematic comparison of the physical properties of ZrSi₂N₄ under trigonal prismatic coordination (2H phase) and octahedral coordination (1T phase). The results show that the 1T phase exhibits a smaller band gap (about 2.23 eV) and significantly reduced carrier effective masses, indicating superior carrier mobility. Meanwhile, the optical absorption spectrum of the 1T phase shows stronger peaks in the 3–5.5 eV range, highlighting tunable optical characteristics. In terms of mechanics and heat transport, the 1T phase demonstrates a higher Young’s modulus, a lower dielectric constant, and a room-temperature thermal conductivity of about 105 W m⁻¹K⁻¹, which is markedly higher than that of the 2H phase. These advantages arise from longer phonon lifetimes and faster phonon group velocities, underscoring the 1T phase’s potential in high-efficiency heat dissipation and thermal management technologies.
In this work, Dr. Ghulam Hussain, a postdoctoral researcher at IAS, is the first author and a co-corresponding author, while Researcher Zheng Wang and Associate Professor Xiaoguang Li serve as corresponding authors. Collaborating institutions include the University of Alabama at Birmingham (USA) and the Institute of Physics, Polish Academy of Sciences. The research was supported by the National Natural Science Foundation of China and the Key Project of the Department of Education of Guangdong Province.
This study not only deepens the understanding of phase-dependent properties in the MA₂Z₄ family of 2D materials but also opens up new avenues for the design of future optoelectronic devices and thermal management applications.
Figure: Electronic structure, optical response, and thermal transport properties of monolayer ZrSi₂N₄ in two different crystalline phases (2H and 1T)
