Development of graphene-based optical detectors for infrared sensing applications

We investigate the development of optical detectors using multilayer graphene for infrared (IR) sensing. Under a zero-bias operation, the graphene-based devices are capable to generate photocurrents in the presences of IR signals with two different wavelengths (830 nm and 1064 nm). The photocurrents induced by electron-hole pair generation are measured in the exfoliated multilayer graphene at room temperature. Moreover, we found that the electron-photon interactions of the devices are significant for multilayer graphene-based devices, and the magnitudes of the photoresponses are higher than that of another well-known nanomaterial - carbon nanotube. These results suggest graphene is suitable for infrared sensing. Here, we demonstrate the design, the fabrication and the experimental results of the graphene-based IR detectors. The structure of the devices consists of a multilayer graphene flake connected with a pair of metal electrodes, which were fabricated using two nanomanipulation techniques: dielectrophoretic manipulation and atomic force microscopic based nanomanipulation. The development of the fabrication process can helps us to make use of graphene for the optoelectronic application.