Engineering Bilayer MoS₂ with Moiré-Dopant Synergy for Advanced Supercapacitor Electrodes

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Two-dimensional (2D) materials offer unique electronic properties.
• Moiré superlattices and atomic doping can tune these properties.
• Quantum capacitance (CQ) is crucial for energy storage applications.

Purpose of the Study:

• Investigate quantum capacitance modulation in Moiré-patterned bilayer MoS2 (mBL-MoS2) via site-specific doping.
• Explore the effects of transition-metal (Nb) and chalcogen (Se) site substitution.
• Establish a framework for designing high-performance supercapacitor electrodes.

Main Methods:

• First-principles calculations.
• Density of states analysis.
• Quantum capacitance calculations (differential and integral).
• Electron localization function (ELF) mapping.
• Bader charge analysis.
• Phonon stability calculations.
• Work function evaluation.

Main Results:

• Interlayer twist in mBL-MoS2 creates periodic potential fluctuations affecting the density of states.
• Niobium (Nb) doping induces a semiconductor-to-metal transition, significantly enhancing electronic delocalization and quantum capacitance.
• Se doping shows a smaller impact due to its isoelectronic nature.
• Nb-doped mBL-MoS2 exhibits superior charge storage capacity in the low-bias domain compared to other 2D materials.

Conclusions:

• Synergistic Moiré engineering and chemical doping offer a powerful strategy for tuning quantum capacitance in 2D materials.
• Nb-doped mBL-MoS2 demonstrates potential as an advanced electrode material for CQ-dominated supercapacitors.
• This work provides a design framework for next-generation energy storage devices.