Field-effect transistors as electrically controllable nonlinear rectifiers for the characterization of terahertz pulses

Abstract

We propose to exploit rectification in field-effect transistors as an electrically controllable higher-order nonlinear phenomenon for the convenient monitoring of the temporal characteristics of THz pulses, for example, by autocorrelation measurements. This option arises because of the existence of a gate-bias-controlled super-linear response at sub-threshold operation conditions when the devices are subjected to THz radiation. We present measurements for different antenna-coupled transistor-based THz detectors (TeraFETs) employing (i) AlGaN/GaN high-electron-mobility and (ii) silicon CMOS field-effect transistors and show that the super-linear behavior in the sub-threshold bias regime is a universal phenomenon to be expected if the amplitude of the high-frequency voltage oscillations exceeds the thermal voltage. The effect is also employed as a tool for the direct determination of the speed of the intrinsic TeraFET response which allows us to avoid limitations set by the read-out circuitry. In particular, we show that the build-up time of the intrinsic rectification signal of a patch-antenna-coupled CMOS detector changes from 20 ps in the deep sub-threshold voltage regime to below 12 ps in the vicinity of the threshold voltage.

Self-Mixing Model of Terahertz Rectification in a Metal Oxide Semiconductor Capacitance

“…On the contrary, a large number of publications have reported measurements on THz rectification by MOS-FET [1,[19][20][21][22][23] using the drain (sometimes the source) as the detection port, with the source (drain) electrode grounded. In such cases, the structure is 2D, and in principle a comparison with the 1D model should not be possible.…”

Silicon Field Effect Transistor as the Nonlinear Detector for Terahertz Autocorellators

“…Recent experiments [ 6 , 35 ] have demonstrated that different FETs, such as Si MOSFETs (metal-oxide-semiconductor field-effect transistor) and AlGaN/GaN HEMTs (high-electron-mobility transistor) at the sub-threshold gate bias, when illuminated by a short-pulse of THz radiation, also exhibit a super-linear response slope before reaching saturation. In this regime, the voltage signal of the transistor is proportional to the radiation power as , where the index n is greater than 1.…”

“…In addition, antenna-coupled field-effect transistors (FET) and the Schottky diodes have recently emerged as useful devices for room-temperature THz autocorrelators [ 4 , 5 ]. We have recently demonstrated that FETs biased in the sub-threshold regime in a certain range of excitation amplitudes exhibit a super-linear response [ 6 ].…”

Advances in Functional Nanomaterials Science

“…THz radiation came into play to derive information from both the spectral response of the molecules and from the changes of the conductivity of the VACNTs. In addition, long-term developments of THz detectors based on antenna-coupled field-effect transistors (Ter-aFETs) by Lisauskas et al [147] had led to the investigation of such THz devices which were optimized in various material sys-tems including Si complementary metal-oxide semiconductor (CMOS) platforms, [147] AlGaN/GaN [148] and graphene. [149] Moreover, power detection and heterodyne operation with single detectors and multipixel arrays were recently explored, and a number of applications studied.…”

“…[149] Moreover, power detection and heterodyne operation with single detectors and multipixel arrays were recently explored, and a number of applications studied. [148] Earlier, Lisauskas et al investigated the interplay of two detection mechanisms using the example of graphene TeraFETs, that is, the Dyakonov-Shur mechanism (the high-frequency extension of classical resistive mixing [147] ) and the hot-carrier photothermal effect (diffusive contribution resulting from the heating of the charge carriers by the THz wave), which is especially strong in graphene and carbon nanotubes. Understandably, to make these THz devices perform well, such interplay must be carefully adjusted.…”