Plasmon Field Effect Transistor (FET) for a Sensing Platform

Student’s name: John Puthiaparambil Home Institution: University of Illinois at Urbana-Champaign NNCI Site: KY Multiscale @ University of Louisville REU Principal Investigator: Dr. Kevin Walsh - Assoc. Dean of Research, Speed School of Engineering, University of Louisville REU Mentor: Sung Jin Kim - Department of Electrical and Computer Engineering, University of Louisville Abstract: There is a growing demand for precise detection and measurement across fields such as medical diagnostics, environmental monitoring, and industrial processes. Traditional methods often lack the sensitivity to detect low concentrations and involve bulky, expensive equipment that delays real-time monitoring. To address these challenges, this study builds on previous research involving the Plasmon Field Effect Transistor (PFET), a hybrid device that leverages Localized Surface Plasmon Resonance (LSPR), an oscillation of electrons generated by light absorption in metallic nanoparticles. By incorporating gold nanoparticles onto the channel of a Field Effect Transistor (FET), the PFET efficiently converts plasmon energy into an electrical signal. When exposed to light, the energized electrons in the gold nanoparticles enhance the drain current, enabling the detection of minute changes in the sensor’s surrounding environment. To further advance the development of the PFET, we report results on how varying the diameters of gold nanoparticles affects the device's sensing range. Gold films of 3nm, 5nm, and 7nm were deposited to form nanoparticles of different diameters, and their respective spectral responses were measured to uncover the relationship between nanoparticle size and sensor performance. Understanding this relationship is crucial for customizing PFETs for specific applications and the development of compact, highly sensitive sensors for a wide range of uses.