Efficient Charge Transfer in Graphene/CrOCl Heterostructures by van der Waals Interfacial Coupling

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) materials offer abundant surface atoms and electrons for interfacial engineering.
• Van der Waals (vdW) heterostructures enable tuning of electronic properties through interfacial charge coupling.
• Graphene/CrOCl heterostructures exhibit intriguing quantum states, but interlayer coupling mechanisms are not fully understood.

Purpose of the Study:

• To provide clear evidence of efficient hole doping in graphene/CrOCl heterostructures.
• To quantify the charge transfer between graphene and CrOCl.
• To elucidate the mechanism behind the observed hole doping.

Main Methods:

• Raman spectroscopy to analyze graphene's electronic structure.
• Electrical transport measurements to assess conductivity changes.
• First-principles calculations (density functional theory) to model charge transfer.

Main Results:

• Significant blue shifts and stiffening of graphene Raman modes indicate efficient hole injection.
• Quantified hole concentration in graphene at approximately 1.2 × 10¹³ cm^-2.
• Observed increase in graphene conductivity consistent with hole doping.
• Calculations confirm electron transfer from graphene to CrOCl due to work function difference and Cl electronegativity.

Conclusions:

• Efficient hole doping of graphene by CrOCl is demonstrated in vdW heterostructures.
• Interfacial charge coupling is a key factor in the electronic properties of graphene/CrOCl.
• Findings contribute to understanding exotic quantum phenomena and engineering 2D heterostructures.