Modeling of floating gate AlGaN/GaN heterostructure-transistor based sensor

This paper presents an analytical model for the estimation of charge concentration in liquid or gas analyte or of the charges induced by biomolecules detected by an AlGaN/GaN High Electron Mobility Transistor (HEMT) based sensor. The adsorbed molecules on the gate surface change the electrostatic potential of the surface. The change in electrostatic condition has been combined with the threshold and drift current equations to calculate the output current of the sensor. The model predicts the change in sensor current with the changes in the density of target analyte and calculates the concentration for which the output saturates at a certain drain-to-source potential.