Doping Mechanisms in Graphene-MoS2 Hybrids

TL;DR

This study combines theoretical and experimental approaches to understand charge doping and potential landscapes in graphene-MoS2 hybrids, revealing impurity and edge effects that influence electronic properties and enable photodetector applications.

Contribution

It provides new insights into how impurities and edges affect doping and potential profiles in graphene-MoS2 hybrids, with implications for device design.

Findings

Electron doping of graphene due to Re impurities in MoS2

Charge reordering caused by MoS2 edges affects graphene potential

Potential shifts in graphene can be controlled via external gates

Abstract

We present a joint theoretical and experimental investigation of charge doping and electronic potential landscapes in hybrid structures composed of graphene and semiconducting single layer MoS2. From first-principles simulations we find electron doping of graphene due to the presence of rhenium impurities in MoS2. Furthermore, we show that MoS2 edges give rise to charge reordering and a potential shift in graphene, which can be controlled through external gate voltages. The interplay of edge and impurity effects allows the use of the graphene-MoS2 hybrid as a photodetector. Spatially resolved photocurrent signals can be used to resolve potential gradients and local doping levels in the sample.