A comparative study of transport properties of monolayer graphene and AlGaN GaN heterostructure
Yarar, Zeki
The electronic transport properties of monolayer graphene are presented with an Ensemble Monte Carlo method where a rejection technique is used to account for the occupancy of the final states after scattering. Acoustic and optic phonon scatterings are considered for intrinsic graphene and in addition, ionized impurity and surface roughness scatterings are considered for the case of dirty graphene. The effect of screening is considered in the ionized impurity scattering of electrons. The time dependence of drift velocity of carriers is obtained where overshoot and undershoot effects are observed for certain values of applied field and material parameters for intrinsic graphene. The field dependence of drift velocity of carriers showed negative differential resistance and disappeared as aco...
Mobility Characteristics of ZnMgO/ZnO Heterostructures with Screening Effects
Yarar, Zeki
The electron mobility characteristics of a ZnMgO/ZnO heterostructure are systematically investigated by an ensemble Monte Carlo method. Screening effects are included in all electron scattering mechanisms. The mobilities are calculated for a temperature range of 4 to 300 K and Mg contents ranging from 8.5 to 44%. In this range, dislocation scattering (DS) and interface roughness scattering (IFR) are highly effective for low and high values of Mg compositions, respectively. Screening effects must be considered in scattering mechanisms to achieve a reasonable agreement with existing experimental results. Our findings could be significant for the design and optimization of ZnO-based devices.