Extraordinary linear dynamic range in laser-defined functionalized graphene photodetectors

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Graphene photodetectors offer mechanical flexibility and broadband response.
• Intrinsic hot-carrier dynamics limit graphene photodetectors' linear dynamic range (LDR) and spatial resolution.
• Current devices show photoresponse deviation at low powers and limited high-resolution capabilities.

Purpose of the Study:

• To engineer photoactive junctions in FeCl3-intercalated graphene using laser irradiation.
• To enhance the linear dynamic range (LDR) of graphene-based photodetectors.
• To overcome limitations in current graphene photodetector technology for improved imaging and sensing.

Main Methods:

• Utilized laser irradiation to engineer photoactive junctions in FeCl3-intercalated graphene.
• Measured photocurrent at the engineered planar junctions.
• Investigated the photoresponse characteristics, including LDR and carrier dynamics.

Main Results:

• Achieved an extraordinary linear photoresponse with an LDR at least 4500 times greater than conventional graphene devices (44 dB).
• Demonstrated complete quenching of hot-carrier effects, resulting in a purely photovoltaic response.
• Maintained high stability against environmental contamination without encapsulation.

Conclusions:

• The novel laser irradiation method significantly enhances the LDR of graphene photodetectors.
• The developed photodetectors exhibit superior stability and a purely photovoltaic response.
• These findings enable the design of ultrathin photodetectors with unprecedented LDR for high-definition imaging and sensing.