Hybrid structures of organic dye and graphene for ultrahigh gain photodetectors

A hybrid structure comprising organic dye molecules (e.g., rhodamine 6G) and graphene was developed for the realization of high-performance optoelectronic devices. The fabricated photodetector offered a broad spectral photo-response across wavelengths in the infrared, visible, and ultraviolet regions, as well as a high responsivity (∼460 A/W at illumination power of 1 μW). The photocurrent generated in the hybrid photodetector (∼mA) was much higher than that generated in a pristine graphene photodetector (<μA). The performance of the dye-sensitized photodetector relied on enhanced photoabsorption and the implementation of a photocurrent gain arising from the photo-excited charges.