Search

In this article, the Gaussian density of states (DOSs) in organic semiconductors is taken into account in order to derive a charge-based compact model for high-speed organic transistors. This physics-based analytical solution provides a continues current equation from below to above threshold regions with considering the deep and shallow trap densities in the organic material, power-law mobility model, and contact resistances effects. The proposed model is verified with the experimental data of our fabricated organic permeable base transistor (OPBT) and shows good agreement with the measurements. OPBTs are of great interest as vertical organic transistors and stand out due to their excellent performance, such as low-voltage operation and high transit frequency.

A physics-based analytical dc compact model for single back-gated MoS2 field effect transistors (FETs) is presented. The model is developed by calculating the charge inside the 2-D layer which is expressed in terms of the Lambert W function that recently has become the standard in SPICE simulators. The current is then calculated in terms of the charge densities at the drain and source ends of the channel. A new mobility model is presented to account for the observed superlinear current increase above a certain gate voltage. Despite the simplicity of the model, it shows very good agreement with the experimental data as well as the possibility to be extended to model the double-gate MoS2 FETs.

In this work, by altering oxygen partial pressure (OPP) and sputtering power ( ${P}_{\text {RF}}$ ) of the radio frequency (RF) magnetron sputtering process, we investigate electrical evolution of the p-type SnOx film and transistor. Herein, combining device current–voltage (such as ON-state current and field-effect mobility), low-frequency noise (LFN), and gate-bias-stress characteristics, we find that the optimal OPP range is 4.8%–7.2% for the SnOx film deposition at ${P}_{\text {RF}}$ of 70 and 30 W. Based on X-ray photoelectron spectroscopy (XPS), the SnOx films deposited at high power (70 W) show less sensitivity to OPP, which leads to the slow transition of internal Sn2+, Sn4+ states, and a relatively large process window. Furthermore, the defect states inside the SnOx are analyzed. The oxygen interstitials (Oi), as deep acceptors, keep inactive regardless of the external bias. The oxygen vacancies (Vo) and the ionized Vo2+ states, which act as the electron traps, get suppressed and are attributed to the ambipolar behavior in the SnOx transistor, while increasing the OPP. This work benefit lies in a comprehensive analysis of the sputtering process parameters impact on SnOx film and transistor properties and their underlying defects.

Previously, we transformed the linear drain bias asymptote equation for the MOSFET drain current in the saturation regime from the "intrinsic" case into "extrinsic" case with accounting for the velocity saturation effect. We obtained the equation for the drain current that yielded the nonlinear dependence on the "extrinsic" drain bias in saturation regime in an implicit form. We derived the equation for the differential conductance of the MOSFET at the "saturation point" and proposed a linear approximation for the dependence of the drain current on the "extrinsic" drain bias in the saturation regime for not very high drain bias when nonlinear effects can be neglected. In this paper, we investigate the asymptotic behavior of the implicit equation for the drain current in case when "extrinsic" drain bias tends to infinity. We propose the nonlinear approximation for the drain current asymptotic that describes a slow current rise to its limiting value when the "extrinsic" drain bias tends to infinity. This approximation is based on analytical solution of quartic equation that can be solved easily enough using Ferrari's method.

Previously, we transformed the linear drain bias asymptote equation for the MOSFET drain current in the saturation regime from the “intrinsic” case into “extrinsic” case with accounting for the velocity saturation effect. We obtained the equation for the drain current that yielded the nonlinear dependence on the “extrinsic” drain bias in saturation regime in an implicit form. We derived the equation for the differential conductance of the MOSFET at the “saturation point” and proposed a linear approximation for the dependence of the drain current on the “extrinsic” drain bias in the saturation regime for not very high drain bias when nonlinear effects can be neglected. In this paper, we investigate the asymptotic behavior of the implicit equation for the drain current in case when “extrinsic” drain bias tends to infinity. We propose the nonlinear approximation for the drain current asymptotic that describes a slow current rise to its limiting value when the “extrinsic” drain bias tends to infinity. This approximation is based on analytical solution of quartic equation that can be solved easily enough using Ferrari's method.