Transport characteristics and dwell time in a bilayer phosphorene barrier

Abstract

In this paper, transport properties, dwell time and electron conductance were theoretically investigated through a rectangular electrostatic potential barrier in bilayer phosphorene and compared the results with monolayer phosphorene and graphene. It has been shown that in bilayer phosphorene, in the presence of an interlayer induced bias, a four-band approximation describes transport process in the system. The results show that interlayer bias parameter drastically affect transport properties. These effects include: (1) appearance of eight transmission and reflection coefficients from a band within the same band and between the two bands; (2) appearance of the anti-Klein tunnelling phenomenon and tuning the bias of system in such a way which is observed in specified biases and removed in other biases; (3) tuning conductance of the system. Results of dwell time in bilayer phosphorene show that this parameter in terms of barrier thickness does not have a strictly ascending behaviour and in limited range of incident energies (incident angles), the dwell time in the barrier reduces significantly which can be exploited in designing switching devices in nano-electronics. We found that increasing the interlayer bias decreases the intrinsic gap of the bilayer phosphorene which enables us to control the electron transmission rate in the system. In addition, our findings also demonstrate that by tuning the interlayer bias, a large electrical conductance can be achieved which can be used in semiconductor technology. Our study could serve as a basis for investigations of the basic physics of tunnelling mechanisms and using bilayer phosphorene as a proper candidate in low dimensional semiconductor industry.