研究目的
To study the difference in electronic and optical properties of bulk and monolayer zirconium sulfide by applying the APW + lo method in the framework of density functional theory.
研究成果
Zirconium sulfide is an indirect bandgap semiconductor with the band gap energy from 1.2 eV to 2 eV. The strong hybridization of sulfur 3-p orbital and zirconium 3-d orbital confirms the strong covalent bond between Zr and S atoms. At energy below 10 eV, the ZrS2-based compounds have strong anisotropic optical behavior. The dielectric function shows that zirconium sulfide has reflectivity at high energy. Zirconium sulfide has best light absorption in the region of visible light to mid-ultraviolet wave length. The monolayer zirconium inherits familiar electronic and optical behaviors of bulk zirconium. At the same time, the 2D compound also exhibits its own perspective properties in photovoltaic material with optimal energy band gap near 2 eV, in sensor application with more peaks at the valence band maximum and sharper peaks of absorption curve. Furthermore, the loss energy in the 2D zirconium is even higher than the one in bulk structure, this suggests a promising material for plasmon application.
研究不足
The lack of Hartree-Fock exchange-correlation may lead to underestimated band gap of monolayer in comparison with experimental values.