This paper presents the negative differential resistance (NDR) behavior of an MoS2 armchair nanoribbon double-gate field effect transistor. The large peak-to-valley current ratio (PVCR) of 2.58 × 102 with a peak current value of − 0.8 μA is achieved with the presented device configuration. A 5-nm channel length device was considered for the study and an extended Hückel model with nonequilibrium Green’s function method is used for the simulation. A phosphorus atom is used as a substitutional dopant at the sulfur site of the MoS2 field effect transistor near the source and drain regions. The PVCR of the device can be controlled by applying a gate voltage. The achieved subthreshold slope of the device is 88 mV/decade with Ion/Ioff value of 1011 at 300 K. The other parameters such as peak current and NDR voltage window are analyzed. The proposed device configuration shows the potentiality of MoS2 armchair nanoribbon material for future small length scale electronic device applications. © 2019, The Minerals, Metals & Materials Society.