Photoconductive response of a Field-Effect Transistor through the traps effect

Abstract

In this paper, the photoconductive parameters of Field-Effect Transistors (FETs) excited by high-frequency optical source is studied. The FETs plasma oscillations dominated in the Terahertz (THz) range demonstrates their important effect related to THz emission and detection at room temperature. The study taking into account the plasma modes of FETs which can be coupled with photoexcitation optical pulse. Particularly, the model using the excess carriers flow through the traps density and the small-signal response of Field-Effect Transistors to describe the photoconductivity and the drain current in external circuit. The effect of the carriers relaxation time, the excited wavelength and the channel plasma modes on photoexcited FETs behavior is investigated. This leads to the possibilities of increasing the photoconductive contribution in total current by coupling both the microwave and optical FET proprieties.