Impact of Phonon Scattering on the Negative-Differential-Resistance Behavior in Graphene Nanoribbon p-n Junctions

In this paper, the effect of electron-phonon scattering on the negative differential resistance of graphene nanoribbon p-n junctions is investigated. The results show that the optical phonon scattering, due to inelasticity, significantly increases the valley current such that the peak-to-valley ratio decreases several orders of magnitude compared to ballistic approximation. It also shifts up the valley voltage. The former effect manifests itself more in structures with a smaller band gap and better ballistic characteristics. We show that it remains remarkable in different lengths of the transition region and severely affects the performance of the device. The results also show that phonon scattering plays a significant role even in ultrascaled nanodevices.