An ultra-broadband single-component fractional-order capacitor using MoS₂-ferroelectric polymer composite

The phase angle of a fractional-order capacitor's (FOC) impedance has a constant value between $−90°$ and $0°$⁠. Maintaining this value over a broad frequency band is of utmost importance since it increases the applicability of the electrical circuit that employs the fractional-order capacitor (FOC). In this work, a molybdenum disulfide (MoS₂)-ferroelectric polymer composite is used to design/fabricate an FOC. The resulting FOC's bandwidth of operation, which is defined as the frequency band where the variation in the phase angle is no more than $±4°$⁠, is five decades between 100 Hz and 10 MHz, a 3 decades improvement over the best reported state of the art. The value of the constant phase angle can be tuned from $−80°$ to $−58°$ by changing the type of the ferroelectric polymer in the composite and the volume ratio of MoS₂. The results presented in this work demonstrate the potential of the FOCs fabricated using MoS₂-ferroelectric polymer composites in robust and accurate realization of various electrical systems.