High Photocurrent in Gated Graphene–Silicon Hybrid Photodiodes

Abstract

Graphene/silicon (G/Si) heterojunction based devices have been demonstrated as high responsivity photodetectors that are potentially compatible with semiconductor technology. Such G/Si Schottky junction diodes are typically in parallel with gated G/silicon dioxide (SiO2)/Si areas, where the graphene is contacted. Here, we utilize scanning photocurrent measurements to investigate the spatial distribution and explain the physical origin of photocurrent generation in these devices. We observe distinctly higher photocurrents underneath the isolating region of graphene on SiO2 adjacent to the Schottky junction of G/Si. A certain threshold voltage (VT) is required before this can be observed, and its origins are similar to that of the threshold voltage in metal oxide semiconductor field effect transistors. A physical model serves to explain the large photocurrents underneath SiO2 by the formation of an inversion layer in Si. Our findings contribute to a basic understanding of graphene/semiconductor hybrid devices which, in turn, can help in designing efficient optoelectronic devices and systems based on such 2D/3D heterojunctions.

Electron Transport across Vertical Silicon/MoS2/Graphene Heterostructures: Towards Efficient Emitter Diodes for Graphene Base Hot Electron Transistors

“…S4, in supporting information). A comparison of the room temperature I-V characteristics of the present devices with the results from "graphene/n-Si" Schottky diodes intensively studied by our research group[39][40][41] clearly indicates the electrical impact of MoS2 in the present structures.…”

High Responsivity and Quantum Efficiency of Graphene/Silicon Photodiodes Achieved by Interdigitating Schottky and Gated Regions

“…Motivated by our previous findings, 3 diodes with interdigitated G/Si (Schottky) and graphene/insulator/silicon (GIS) regions were designed, where the insulated regions made up a significant portion of the active device area. Two different types of diodes were fabricated per chip.…”

2D In2S3 Nanoflake Coupled with Graphene toward High‐Sensitivity and Fast‐Response Bulk‐Silicon Schottky Photodetector

“…The natural defect of the vacancy causes multiple defect states near the edge of the band, which makes it sensitive to the NIR light. Especially, 2D form of In 2 S 3 releases the strict lattice mismatching requirement and makes it compatible with graphene and matured silicon‐based process …”

“…Especially, 2D form of In 2 S 3 releases the strict lattice mismatching requirement and makes it compatible with graphene and matured silicon-based process. [16][17][18] Herein, we construct a highly sensitive In 2 S 3 /graphene/Si Schottky PD. The introduction of In 2 S 3 not only strengthens the light absorption of graphene/Si, promotes highly efficient charge separation in the graphene/Si interface, but also brings photoconductive gain.…”