Nonlinear Capacitance Behavior in Graphene/Carbon Nanotube Hybrid Films: An in-Depth Analysis

Graphene/carbon nanotube (CNT) hybrid films exhibit pronounced nonlinear capacitance–voltage(C–V) characteristics as a function of applied bias, typically showing multiple distinct peaks and valleys. Thisstudy presents a combined experimental and theoretical investigation of the underlying mechanisms governing such nonlinearity. By integrating previously reported C–V data and microstructural observations with a newly developed quantitative model, we demonstrate that the density of interfacial nanojunctions (Nₖ) predominantly determines the amplitude of the observed capacitance peaks. The proposed Distributed Multi Peak Hybrid Model (DMHM) quantitatively correlates structural parameters with electrical responses, while quantum capacitance and interfacial polarization are shown to have secondary modulating effects. This comprehensive analysis elucidates the interplay of microstructure and interfacial physics, providing valuable insight for designing optimized graphene/CNT based electronic devices.