Performance limits for field effect transistors as terahertz detectors

We present estimates of the performance limits of terahertz detectors based on the field effect transistors (FETs) operating in the regime of broadband detection. The maximal responsivity is predicted for short-channel FETs in the subthreshold regime. The conversion efficiency of the device, Q (defined as the ratio of the power dissipated by radiation-induced dc current to the THz dissipated power) has an absolute maximum as a function of two variables: the power and the frequency of the incoming radiation. The maximal value of Q is on the order of 10%. (C) 2013 AIP Publishing LLC.