A general method for large-area and broadband enhancing photoresponsivity in graphene photodetectors

作者:Xing, Fei; Xin, Wei; Jiang, Wen Shuai; Liu, Zhi Bo*; Tian, Jian Guo
来源:Applied Physics Letters, 2015, 107(16): 163110.
DOI:10.1063/1.4934497

摘要

We report on a general method for broadband responsivity enhancement in graphene photodetectors based on the sandwiched graphene structure under total internal reflection. The optical absorption is similar to 25% for transverse electric waves for pure monolayer graphene, and the responsivity of pure monolayer graphene photodetectors is 0.012 A/W, which is one or two orders of magnitude larger than the normal incidence excitation. The enhanced responsivity covers a wide wavelength range from 300 to 1550 nm. Further, this method is not limited by the device, and it is a general method used to improve the light-graphene coupling, thus increasing the responsivity of graphene photodetectors largely. And this method allows large area preparation to meet the needs of the free space light detections.