Plasmonic Metal-Infused Laser-Induced Graphene for Enhanced Photodetection

Laser-Induced Graphene (LIG) is a promising platform for next-generation flexible photodetectors due to its high conductivity, scalability, and low-cost fabrication. However, its optical-to-electrical conversion efficiency remains limited by weak light–matter interaction. In this work, we enhance LIG photodetection performance through the in-situ infusion of plasmonic palladium nanoparticles into the polymer precursor prior to laser carbonization. During laser processing, the nanoparticles become embedded within the porous graphene microstructure, enabling localized electromagnetic field enhancement via surface plasmon resonance. Electrical characterization under UV illumination demonstrates improved resistance modulation and consistent ON/OFF cycling behavior in Pd-infused LIG compared to bare LIG samples. These initial results confirm plasmon-assisted photocarrier generation and highlight an effective, single-step approach to improving responsivity in flexible photodetectors. Future efforts will investigate wavelength-dependent response and additional plasmonic materials such as silver and gold nanoparticles.

Hello, my name is Graham Harper from the Mechanical Engineering Department at George Mason University. Today, I’ll be presenting my research about Plasmonic Metal-Infused Laser-Induced Graphene for Enhanced Photodetection.

Photodetectors are critical components in environmental and optical sensing systems. However, many conventional photodetectors are expensive to fabricate and lack flexibility.
Laser-Induced Graphene offers a more scalable and low-cost alternative due to its conductive porous structure and ability to be processed on flexible substrates.
The challenge is improving how efficiently it converts light into a measurable electrical signal.

One promising way to improve photodetection is by taking advantage of surface plasmon resonance.
Metal nanoparticles, such as palladium, can enhance local electromagnetic fields when illuminated, generating more charge carriers in the device.
By infusing metal nanoparticles directly into the polymer before laser conversion, the plasmonic functionality becomes embedded within the graphene structure.
Our hypothesis is that metal infused laser-induced graphene will perform better under illumination than bare laser-induced graphene.

Our objective is to fabricate laser induced graphene using a UV or CO₂ laser, characterize its structure and electrical properties, and measure photodetection performance under illumination.
The main goal is to determine whether palladium-embedded laser induced graphene produces enhanced optical-electrical response.

To create Palladium infused laser-induced graphene, a palladium-doped polymer solution is spin-coated for thickness uniformity. A laser induces carbonization to form conductive graphene that has palladium nanoparticles dispersed throughout.
Electrical contacts are added using silver paste and copper wires.
Samples are tested under a 62 mA UV laser while recording resistance changes as the light switches on and off.

Our results show a clear increase in resistance change under illumination for the Pd-infused samples.
The cycling data demonstrates consistent ON/OFF behavior with strong repeatability, confirming plasmon-assisted photocarrier generation and successful light response.

We successfully created plasmonically enhanced laser-induced graphene, palladium-infused laser-induced graphene showed stronger optical-electrical response, and the fabrication method remains low-cost and scalable.
This demonstrates that plasmonic nanoparticles provide an effective pathway to improve flexible photodetectors.

Future goals include testing silver and gold nanoparticles with stronger plasmonic response, expanding testing to more wavelengths beyond UV, conducting durability and reliability testing, and performing additional structural analysis (Raman, SEM).

Thanks to the Undergraduate Research Scholars Program, Dr. Pilgyu Kang, and the Nanomaterials Lab at GMU for their support.