A novel broadband photodetector realized using graphene based heterojunction on a silicon substrate

Photodetectors are of great interest in several technological applications thanks to their capability to convert an opticalsignal into an electrical one through light-matter interactions. In particular, broadband photodetectors are used in multipleapplications such as environmental monitoring, imaging, fire detection, and astronomical observations.We present a two-dimensional photodiode heterojunction based on reduced graphene oxide (rGO) deposited on an n-typeSilicon substrate. We report on the electro-optical properties of the device that have been measured in dark and lightconditions into a spectral range from UV to IR. The room temperature current-voltage (I-V) measurements of rGO/n-Siphotodetector exhibits a reverse saturation current linearly dependent on the light power. The main figures of merit of thephotodetector such as linearity and responsivity have been evaluated and compared with the recent progress obtainedsubstituting the rGO with a graphene single layer (Gr) on the similar n-Si substrate. The photoconductive properties andanalysis of the two devices are presented and discussed. Finally, the experimental results demonstrate the feasibility of therGO/n-Si and Gr/n-Si device to detect light from UV to IR light, nominating graphene-based heterojunction as a novelcandidate for the realization of new broadband photodetectors.