Current-Voltage Characterization of Multi-Port Graphene Based Geometric Diodes for High-Frequency Electromagnetic Harvesting

In this contribution, geometric diodes based on graphene patterned with spatial asymmetry have been studied, starting from tight-binding numerical approximation in a self-consistent framework, to verify their potential for electromagnetic (e. m.) harvesting. We report a detailed analysis of coherent charge transport and provide some figures of merit with respect to e. m. rectification, such as, for instance, the asymmetry of the dark current-voltage characteristics. The most important achievement of this work is given by the accurate analysis of the main key physical/geometric parameters that affect the nonlinear response of the diodes, for different configurations and geometries. Owing to the Scattering Matrix approach, introduced elsewhere for coherent transport calculation, it was possible to cascade asymmetric discontinuities and simulate large structures (more than 100K atoms) in a modular fashion. In this way, simulation at the atomistic level can be brought up to the device level to provide guidelines for design and fabrication, in view of practical applications related to clean-energy harvesting/rectification up to infrared and solar-light frequencies.