This paper presents a comprehensive investigation into the ballistic I-V characteristics of nanosheet field-effect transistors (FETs) employing 2D semiconductor materials. By concurrently solving the quantum transport equation in conjunction with the Poisson equation, we offer a rigorous analysis of device performance. Specifically, we examine the case of FINFETs, where the number of sheets equals one, serving as a benchmark for our study. The channel materials under scrutiny consist of monolayer sheets of van der Waals (vdW) 2D semiconductors, demonstrating their potential in advanced device architectures. This research work comprehensively investigates the performance characteristics of nanosheet field-effect transistors (FETs) employing transition metal dichalcogenides (TMDs) as channel materials. Molybdenum disulfide (MoS \(_2\) ), molybdenum diselenide (MoSe \(_2\) ), and molybdenum ditelluride (MoTe \(_2\) ) are all members of the transition metal dichalcogenide (TMD) family. Our computational framework yields multifaceted insights, including I-V characteristics, potential and charge profiles, as well as quantum transmission and local density of states. Through self-consistent numerical simulations, we elucidate the intricate interplay between quantum mechanical effects and device operation, thereby elucidating key design considerations for future nanoscale electronics. This research contributes to advancing the understanding of nano-electronic device design and paves the way for developing high-performance transistors for future technological applications.