Monolayer crumpled graphene-based mechanically and electrically tunable infrared absorbers for high-sensitivity sensing

Enhancing the absorption of infrared light in continuous monolayer graphene layer has received much attention in various optical devices. Here, based on the uniaxial and biaxial crumpled graphene structures, two mechanically and electrically tunable infrared absorbers have been proposed and investigated. We have demonstrated that the near-unity absorption spectra of proposed absorbers are ascribed to the electric resonance modes excited along the sidewalls of crumpled graphene structures, and a broad spectra tunability can be achieved through combing mechanical stretching/compression with the conventional electrostatic doping method. Furthermore, the refractive index sensing capacity of proposed biaxial absorber has been further investigated. Benefiting from the unique stereoscopic morphologies, the sensing sensitivity of each mode of the absorber can reach up to 5.546 and 8.251 µm per refractive index unit, respectively. The broad spectra tunability, high sensing sensitivity as well as flexible structures render it holding promising potentials in high-sensitivity flexible sensing applications.