Modeling demands for nanoscale devices

With the progress of miniaturization the size of electronic devices is presently scaling down into the nanometer region, where quantum mechanical effects play an important role. Appropriate technology computer-aided design tools are essential to explore the physics of nanoscale devices and to find methods to optimize their functionality and performance. In this work we review the approaches to quantum mechanical modeling of carrier transport in nanoscale electronic devices. Numerical analyses for graphene nanoribbons are presented as a case study.