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In this paper, we present the operation principle of an organic metal–insulator–semiconductor (MIS) capacitor where the organic semiconductor is undoped. In spite of a low charge concentration within the semiconductor, this device exhibits a capacitance variation with respect to the applied gate voltage yielding the capacitance–voltage characteristics similar to that of a traditional MIS capacitor based on the doped semiconductor. A physics-based model is developed to derive the charge concentration, surface potential, and the capacitance of the organic MIS capacitor. The model is validated with TCAD simulation results as well as with experimental data obtained from the fabricated organic MIS capacitor consisting of poly(4-vinylphenol) and poly(3-hexylthiophene-2, 5-diyl) as an insulator and a semiconductor, respectively. [ABSTRACT FROM AUTHOR]

We propose the application of ferroelectric (FE)-based transistors, viz., negative capacitance FET (NCFET) and Hysteretic ferroelectric FET (FEFET) in the design of coupled oscillators. The proposed oscillator utilizes hysteretic inverter voltage transfer characteristics, which is achieved by virtue of: 1) negative output conductance (NOC) in NCFETs and 2) hysteretic transfer characteristics in FEFETs. With the aid of output-to-input feedback in the inverter, we show sustained oscillations which are controllable by the gate voltage of the feedback transistor (${V} _{\mathrm {BIAS}}$). With focus on NCFET-based designs, we show that feedback implementation with pass transistor (PT) and transmission gate (TG) yields relaxation and sinusoid-like characteristics, respectively. Such behavior offers promises for dynamically reconfiguring the oscillator dynamics. We report the fundamental frequency (${f}$) in the range of 12 MHz–800 MHz and 0.7 MHz–417 MHz for TG and PT implementations, respectively. We discuss how this approach can be extended to hysteretic FEFET-based designs. We also analyze coupling between two oscillators considering various strengths of coupling capacitance (${C} _{\mathrm {CP}}$). We establish the conditions for synchronization of ${f}$ between the two oscillators with respect to difference in ${f}$ and ${C} _{\mathrm {CP}}$. [ABSTRACT FROM AUTHOR]