High sensitivity active adjustable graphene absorber for refractive index sensing applications

Abstract

In this paper, we proposed a three-band active adjustable perfect absorber, the whole structure is Au-SiO2-Graphene from bottom to top, and the absorber designed shows superior physical mechanism. The properties of active adjustability of absorber can be achieved by regulating the Fermi level of graphene. And we focused on the sensing characteristics of the absorber, the results show that the four significant parameters S(max) is 817.5 nm/RIU, FOM(max) is up to 76.5, Q(max) is 342.1 and detection factor P(min) is 0.01. Then, the sensing performance of the absorber in aqueous solution, 10 %, 20 %, 25 %, 60 % glucose solution and 30 %, 50 % sugar solution was simulated respectively, which proves the high refractive index sensitivity of our absorber. In addition, in the medical field, the specific application of the absorber in measuring the content of hemoglobin molecules in organisms was discussed, and the data demonstrates that the sensing performance of our absorption sensor is good and stable. Compared with the previous work, our absorber has the advantages of multi-band perfect absorption, active adjustability, high refractive index sensitivity, good and stable sensing performance, with which can be used in many fields, such as biosensor, photoelectric detection and so on.