<p>This paper proposes a field-effect transistor featuring a channel composed of a quantum dot based on an armchair graphene nanoribbon. The simulation of this device's structure utilizes the dependence of the energy gap on the width of the one-dimensional armchair graphene nanoribbon to create quantum dots in the channel. A numerical technique known as the transfer matrix method has been employed for the calculations, and Launder's formula has been applied to generate current diagrams. The theoretical analysis demonstrates that the transfer characteristics exhibit oscillatory on–off switching behavior, while the output characteristics show a staircase pattern. Furthermore, the study investigates the mode dependency of the transmission probability and how the width of the armchair graphene nanoribbon affects the output results.</p>