Compact I-V Model for Ambipolar Field-Effect Transistors With 2D Transition Metal Dichalcogenide as Semiconductor

A drain current formula for two-dimensional field-effect transistors with one-shot convergence algorithm

“…The article proves that if this condition is violated, an anomalous current hump will appear on the characteristic transfer curve, which has not yet been emphasized experimentally (as a note: the current humps reported in experiments [15,[30][31][32][33][34][35] occur at lower drain-source biases, which contradicts the theoretically expected higher drain-source biases, and are thus more likely to be caused by significant gate leakage current rather than excess carriers that are not recombined). Although the final proposal seems natural and has even been assumed in previous literature [9,28,36], the QFLPS approach provides a systematic explanation. More importantly, it provides a phase diagram analysis method for understanding device operation modes, covering both ambipolar and unipolar devices.…”

Analyzing Few-Layer and Heterostructure pH-Sensitive 2D-Material Field-Effect Transistors Using a Physics-Based SPICE Compact Model

“…Parts a and b of Figure represent the explicit SPs evaluated at the source side (ψ ss,hetro ) and drain side (ψ sd,hetero ) for a MoS 2 /WSe 2 dual-channel heterostructure ISFET. The existence of a dual channel in a heterostructure ISFET necessitates including the contribution of both the electron and hole currents I ds,e and I ds,h in the final current expression of heterostructure ISFETs. − Depending on the dominance of the carriers (electrons or holes) in the channel, the corresponding current expression for the heterostructure ISFETs reduces to either the electron or hole current. The ambipolar drain current in the heterostructure ISFETs ( I ds,hetero ) can be captured as I ds , hetero = f ( Q se , Q sh ) ( I ds , e μ eff , e + I ds , h μ eff , h ) where f ( Q se , Q sh ) = Q se μ eff , normale + Q sh μ eff , normalh Q se + Q sh where I ds,e ( I ds,h ) is the drain current due to electrons (holes) flowing in the heterostructure ISFETs, μ eff,e (μ eff,h ) is the electron (hole) effective mobility, and Q se ( Q sh ) represents the electron (hole) charge density.…”

“…Another approach for obtaining the super-Nernstian response in DG-ISFETs, which is independent of the gate–insulator thickness is by establishing the van der Waals vertical heterostructures between different TMDs. − The use of an atomically thin 2D-heterostructure channel eliminates the need for a thicker back-gate oxide required for attaining high sensitivity in DG-ISFETs, enabling these heterostructure ISFETs to be more suitable for ultrascaled point-of-care (POC) diagnostic applications. The compact models for 2D-material FETs − cannot be used to predict the behavior of such ion-sensing 2D-FETs in electrochemical environments, and an in-depth comprehension of the underlying physics governing these 2D-ISFETs necessitates the development of new accurate device physics-based models. The existing body of literature on the compact models for 2D-ISFETs remains notably scarce.…”