چكيده به لاتين
In recent years, investigation of transport properties, tunneling procedures and specially tunneling times through potential barriers based on two-dimensional materials such as graphene and silicene have been widely concerned. But, limitation of zero band gap of graphene and being synthesized on metal substrates of silicene, has restricted using of them in nano-electronic circuits. Phosphorene as a semiconductor with high carrier mobility, tunable band gap and anisotropic properties could be a proper candidate for using in semiconductor technology. In this thesis, we have studied transmitting of pseudo-electrons through potential barrier based on monolayer phosphorene in presence of exchange interaction. We have computed the spinor wave functions of pseudo-electrons for inside and outside regions of barrier and presented a compact and exact analytical expression for transmission and reflection rates, dwell time and conductance in system. Also, in another investigation, we have probed based on a tight-binding approximation, electron transportation, conductance and dwell time for bilayer phosphorene in a four band model.
Our results for monolayer phosphorene show that the barrier is transparent for incident particles for a wide range of incident angles in energies higher than barrier height. Furthermore, we have showed that the spin of particles has an important role in tunneling time as well as barrier thickness, incident energy and barrier height. Our investigation for bilayer phosphorene demonstrate that by applying an induced external bias between two layers we can observe new effects such as anti-Klein phenomenon. On the other hand, our calculations show that we can observe appearing and removal of this phenomenon via tuning the bias. The existence of this bias leads to appearing 4 transmission and reflection rate parameter (instead of 2 parameter in two band approximation) in system. We have indicated that with tuning the bias, exact controlling of the conductance and changing of tunneling time in the system would be possible. We found that for zero bias, a two band model for describing the transport properties of the system is enough. We have comprehensively compared between the transport characteristics and dwell time of phsphorene and graphene in all over of our thesis.
