Temperature controlled photorefractive effect of the graphene

摘要

Abstract Carrier fluctuation of the graphene is closely related to the performance of graphene-based photoelectronic devices. Photogenerated carrier of the graphene can be deduced by investigating its photorefractive index which is closely related to the injected light power and temperature. Using a graphene cladding optical fiber Michelson interferometer (MI), temperature controlled photorefractive effect of the graphene is explored by measuring the interference spectrum of the MI. Experimental results show that the refractive index of the graphene is modulated linearly by the optical power increasing from 1.49 to 14.86 mW, and corresponding to different temperatures from 293 to 373?K, it has different modulation efficiency, such as 22.4?pm/mW at 293?K, 15.3?pm/mW at 308?K, 9.6?pm/mW at 323?K, and 7.6?pm/mW at 373?K, respectively. The higher the temperature, the lower the modulation efficiency, which due to the carrier in the energy band of the graphene are inversely proportional to the temperature at near room-temperature range. Therefore, we can get a conclusion that the photorefractive index of graphene can be significantly controlled by temperature, and this effect should be considered and utilized in the design of graphene-based photoelectronic devices.