Thermal noise-limited sensitivity of FET-based terahertz detectors

Here we present a detailed study on estimation of noise-dependent parameters, such as signal-to-noise ratio (SNR) or noise equivalent power (NEP), of field-effect-transistor based terahertz detectors (TeraFETs). Commonly, these parameters are estimated from a well-known assumption, that detector's performance is limited by the thermal noise of transistor's channel. However, practice shows that the influence of other noise sources or transient effects is considerable. We summarize TeraFET noise measurements performed on different material systems based transistors, such as AlGaN/GaN, AlGaAs/GaAs, silicon CMOS, and monolayer graphene. We have achieved a good agreement between thermal noise and measured data. However, attention has to be paid to gate leakage currents and slow defect charging and discharging effects, which can strongly influence TeraFET's performance estimation.