Sushil Kumar Jain

Bio: Sushil Kumar Jain is an academic researcher from Malaviya National Institute of Technology, Jaipur. The author has contributed to research in topics: Transistor & Semiconductor. The author has an hindex of 2, co-authored 3 publications receiving 14 citations.

Numerical Simulation and Compact Modeling of Thin Film Transistors for Future Flexible Electronics

Abstract: In this chapter, we present a finite element method (FEM)-based numerical device simulation of low-voltage DNTT-based organic thin film transistor (OTFT) by considering field-dependent mobility model and double-peak Gaussian density of states model. Device simulation model is able to reproduce output characteristics in linear and saturation region and transfer characteristics below and above threshold region. We also demonstrate an approach for compact modeling and compact model parameter extraction of organic thin film transistors (OTFTs) using universal organic TFT (UOTFT) model by comparing the compact modeling results with the experimental results. Results obtained from technology computer-aided design (TCAD) simulation and compact modeling are compared and contrasted with experimental results. Further we present simulations of voltage transfer characteristic (VTC) plot of polymer P-channel thin film transistor (PTFT)-based inverter to assess the compact model against simple logic circuit simulation using SmartSpice and Gateway.

Performance Investigation of Organic Thin Film Transistor on Varying Thickness of Semiconductor Material: An Experimentally Verified Simulation Study

Abstract: Physics-based two-dimensional numerical simulations are performed to analyze the device characteristics of tri-isopropylsilylethynyl (TIPS)-pentacene organic thin-film transistor (OTFT) fabricated using drop-casting technique. Further, using simulation technique enabling calibration this paper also presents the systematic study of the impact of active layer (TIPS-pentacene) thickness on device characteristics. The extracted parameters such as electric field intensity, current density, current On/Off ratio, and mobility exhibit variation with scaling down in active layer thickness from 500 to 100 nm. The study also revealed that Off current and On/Off current ratio (IOn/IOff) is highly dependent on the thickness of the semiconductor layer. Furthermore, the highest value of IOn/IOff is obtained at 100-nm thickness of TIPS-pentacene, which can be used for various fast-switching applications in digital circuits. Simulated results are not only reasonably matching with experimental results but also provide insight on charge transportation at the semiconductor-dielectric interface and in the bulk of TIPS-pentacene layer.

Impurity Conduction at Low Concentrations.

Abstract: The conductivity of an $n$-type semiconductor has been calculated in the region of low-temperature $T$ and low impurity concentration ${n}_{D}$. The model is that of phonon-induced electron hopping from donor site to donor site where a fraction $K$ of the sites is vacant due to compensation. To first order in the electric field, the solution to the steady-state and current equations is shown to be equivalent to the solution of a linear resistance network. The network resistance is evaluated and the result shows that the $T$ dependence of the resistivity is $\ensuremath{\rho}\ensuremath{\propto}\mathrm{exp}(\frac{{\ensuremath{\epsilon}}_{3}}{\mathrm{kT}})$. For small $K$, ${\ensuremath{\epsilon}}_{3}=(\frac{{e}^{2}}{{\ensuremath{\kappa}}_{0}}){(\frac{4\ensuremath{\pi}{n}_{D}}{3})}^{\frac{1}{3}}(1\ensuremath{-}1.35{K}^{\frac{1}{3}})$, where ${\ensuremath{\kappa}}_{0}$ is the dielectric constant. At higher $K$, ${\ensuremath{\epsilon}}_{3}$ and $\ensuremath{\rho}$ attain a minimum near $K=0.5$. The dependence on ${n}_{D}$ is extracted; the agreement of the latter and of ${\ensuremath{\epsilon}}_{3}$ with experiment is satisfactory. The magnitude of $\ensuremath{\rho}$ is in fair agreement with experiment. The influence of excited donor states on $\ensuremath{\rho}$ is discussed.

Optimization of OFET Performance with Pentacene as Organic Material

Abstract: Pentacene is widely used in organic transistors as an organic semiconductor material. The conductivity of pentacene is enhanced in recent days, which helps in improving the device characteristics of organic transistors providing additional benefit of low-cost and flexible devices. Modeling and simulation of such devices are constructive in analyzing device characteristics. Here, in this paper modeling and simulation of four different configurations of organic transistor – two on the basis of the bottom gate and two on the basis of the top gate – is done in order to analyze the transfer and output characteristics. Off current of 10-15 A, and low subthreshold swing of 0.347 V/decade was observed.