Electrical Model of a Single Pixel SOI Phototransistor Relying on the Transient Charge Pumping Technique

In this paper a floating body partially depleted SOI MOSFET used to measure light intensity using the transient charge pumping (Okhonin, Nagoga and Fazan, 2002) is modeled through an equivalent electrical circuit. Essentially, photogenerated charges of the MOSFET are converted into a charge pumping frequency needed to maintain the drain current constant during the illumination. This contrasts with other conventional methods that rely on an accurate quantification of the drain current to measure the light intensity. Flux densities as low as 2 mW/m² were measured, thus confirming the potential of this approach.