Tunable Plasmonic Devices by Integrating Graphene with Ferroelectric Nanocavity

Abstract Graphene plasmons can become the fundamental of novel conceptual photonic devices, resulting from their unique characteristics containing excitation at room temperature and tunable spectral selectivity in different frequencies. The pursuit of efficiently exciting and manipulating graphene plasmons is necessary and significant for high‐performance devices. Here, the graphene plasmon wave propagating in ferroelectric nanocavity array is investigated. It has been experimentally shown that the periodic ferroelectric polarizations can be used for doping graphene into desired spatial carrier density patterns. Based on a theoretical model that considers periodic ununiform conductivity across graphene sheet, the simulation results show surface plasmon polaritons (SPP) in graphene can be excited by an incident light in a similar way to the excitation of photonic crystal resonant modes. The graphene SPP resonance can be tuned from ≈720 to ≈1 000 cm⁻¹ by rescaling the ferroelectric nanocavity array, and from ≈540 to ≈780 cm⁻¹ by dynamically changing the applied gate voltage. This strategy of graphene carrier engineering to excite SPP offers a promising way for large‐scale, nondestructive fabrication of novel graphene photonic devices.