This paper presents numerical simulation and compact modeling of 2,7-Dioctyl {1} benzothieno {3,2-b}{1} benzothiophene (C8-BTBT-C8) organic semiconductor-based TFT. It shows the entire modeling process flow of this organic semiconductor (OSC) and tests the device realization using a ring oscillator. The paper comprises OSC characterisation, band-gap modeling, electrostatic modeling, and capacitance modeling. The TCAD model consists of the Hopping and Pool Frenkel premise and characterizes the Density of State (DOS) for traps in deep and tail states. The findings from this research provide valuable information for improving OTFT models, enhancing their predictive accuracy, and advancing the understanding of organic semiconductor device behavior. The electrostatics demonstrate device structure dependency