Ashkhen Yesayan and Jean-Michel Sallese
Modeling and Sensitivity Analysis of GaN HEMT Biosensor
Biosensors: Section Biosensor and Bioelectronic Devices (2026), 16(9), 520
DOI: 10.3390/bios16090520
* STI-EDLab, EPFL, Lausanne (CH)
Abstract: Gallium nitride (GaN) high-electron-mobility transistor (HEMT) biosensors have recently emerged as promising platforms for highly sensitive and label-free detection of biomolecules. Their exceptional electrical properties, including high carrier mobility, together with the wide bandgap and strong chemical bonds of GaN materials, provide excellent stability under high temperatures, ionizing radiation, and chemically harsh environments. Despite significant experimental progress, comprehensive analytical models capable of linking biomolecular recognition events to the electrical response of GaN biosensors remain limited. This work presents a physics-based, design-oriented analytical modeling framework for AlGaN/GaN HEMT biosensors. The model incorporates biomolecular binding kinetics, the dielectric properties of the hybrid system, and electrostatic coupling to the transistor channel conductivity. Numerical simulations are performed using commercial multiphysics software to validate the analytical model. The developed framework provides physical insight into the mechanisms governing biosensor operation and offers practical guidelines for the optimization and comparative assessment of HEMT/MIS-HEMT biosensor architectures.
FIG: Typical GaN HEMT structure with a simplified representation of the functionalization and diffuse layers (not to scale) and corresponding IV plot at different gating potentials induced by analyte concentration variations, obtained from the analytical model and numerical simulations.
Acknowledgments: This work was funded by the SNSF Foundation project 200021 213116. During the preparation of this manuscript the authors used GPT-5.6 Luna to draw the picture in Figure 1. The authors have reviewed and edited the output and take full responsibility for the content.
