Ultraviolet absorption band engineering of graphene by integrated plasmonic structures

In the ultraviolet range, it is still a critical challenge to enhance and engineer light absorption inside graphene for optoelectronic applications. Here, we propose a metal-dielectric-metal plasmonic structure to achieve a high absorption ratio of ultraviolet incident light inside graphene. The absorption of ultraviolet light in single layer graphene is enhanced up to 44%, while the absorption spectrum can be tuned by optimizing the dimensions of the integrated structure. Furthermore, the structure can tolerate a wide range of incident angles, while the improved structure with aluminum nanoparticles also shows polarization-independent feature. Besides, the effect of surface oxidation on this structure is also revealed. Our research provides an important theoretical guide for designing novel optoelectronic devices based on graphene in the ultraviolet region.