Performance Limits for Field Effect Transistors as Terahertz Detectors

TL;DR

This paper estimates the fundamental performance limits of field effect transistors used as broadband terahertz detectors, focusing on responsivity and conversion efficiency, and identifies maximum achievable efficiency under ideal conditions.

Contribution

It provides theoretical predictions of the maximum responsivity and conversion efficiency of FET-based terahertz detectors, highlighting optimal regimes and fundamental limits.

Findings

Maximal responsivity occurs in short-channel FETs in the subthreshold regime.

Conversion efficiency Q has an absolute maximum around 10%.

Efficiency depends on radiation power and frequency, with a theoretical upper bound.

Abstract

We present estimates of the performance limits of terahertz detectors based on the field effect transistors (FET) in the regime of broadband detection. The maximal responsivity is predicted for short-channel FETs in the subthreshold regime. We also calculate the conversion efficiency Q of the device defined as the ratio of the power dissipated by radiation-induced dc current to the THz dissipated power. We show that Q 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%