Effect of tensile biaxial strain on the quantum capacitance of 1H two-dimensional NbSe2 via density functional theory calculations

Abstract

The effect of biaxial straining on the quantum capacitance of a two-dimensional transition-metal dichalcogenide (TMD) material, 1H-NbSe₂ was investigated using density functional theory (DFT). Moreover, its band structure was analyzed. Results show that the quantum capacitance of 1H-NbSe₂ enhances as it is subjected to more tensile biaxial straining. The changes in the DOS profiles of 1H-NbSe₂, such as the formation of localized states, further localization of states near the Fermi level, and the shifting of DOS peaks towards the Fermi level were found to explain the improvement of their quantum capacitance values through tensile biaxial straining. The results of this study can be used as a theoretical basis to engineer high-capacitance NbSe₂-based supercapacitors.