Synergistic integration of atomic-scale doping and Moiré superlattices opens up new possibilities for manipulating the electrical characteristics of two-dimensional (2D) materials. Here, we report the first thorough first-principles investigation of site-specific chemical doping-based quantum capacitance (CQ) modulation in Moiré-patterned bilayer MoS2 (mBL-MoS2). Periodic potential fluctuations caused by a 21.79° interlayer twist change the density of states close to the Fermi level. By performing transition-metal-site substitution (Mo → Nb) and chalcogen-site substitution (S → Se), further improvements are achieved. Nb doping, which induces a semiconductor-to-metal transition, greatly enhances electronic delocalization and quantum capacitance, whereas Se doping has a comparatively smaller impact owing to its isoelectronic nature with S. The structural and electronic tunability of these systems is confirmed by a comprehensive analysis that includes electronic structure, differential and integral CQ calculations, electron localization function (ELF) mapping, Bader charge analysis, phonon stability, and work function evaluation. The superior charge storage capacity of Nb-doped mBL-MoS2 in the low-bias domain is demonstrated by benchmarking against other 2D materials. These results show how Moiré engineering and chemical doping can work together to create a new design framework for CQ-dominated supercapacitor electrodes.
Sruthi et al. (Wed,) studied this question.