Analysis and Modeling of Electrical Parameters in OTFTs with BGTC Configuration

The modeling of electrical parameters in organic thin-film transistors (OTFTs) using the Poole-Frenkel model, with the aim of optimizing the balance between dynamic and static performance aspects. A novel and efficient method is introduced to effectively capture significant nonlinear behaviors in these devices, offering a simplified approach without requiring an in-depth exploration of the internal mechanisms. The device structures investigated include bottom-gate top-contact (BGTC) configurations, in which pentacene is vacuum-deposited as the semiconductor material. The structure is completed with metal gates and a gate dielectric, both fabricated at room temperature, ensuring compatibility with low-cost manufacturing processes. The channel dimensions of the OTFTs are set at a width of 10 mm and a length of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$5 \mu \mathrm{m}$</tex>. To analyze the device behavior, finite element simulations were conducted using the Silvaco 2-D Atlas simulator, providing insights into key electrical parameters such as <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$I_{\text{on}}, I_{\text{off}}$</tex>, subthreshold swing (SS), and the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$I_{\text{on}}/ I_{\text{off}}$</tex> ratio. The simulation results reveal a significant reduction in the drain-source current, attributed to the limitations in charge carrier mobility within the pentacene semiconductor. Additionally, the impact of varying gate and drain voltages on device performance was evaluated, highlighting the role of material properties and structure in optimizing OTFT efficiency. This work contributes to the ongoing development of high-performance, cost-effective organic semiconductor devices, with a focus on enhancing their overall functionality and application potential in next-generation flexible electronics.