Resonance detection of terahertz radiation in submicrometer field-effect GaAs/AlGaAs transistors with two-dimensional electron gas

Resonance detection of terahertz radiation by submicrometer field-effect GaAs/AlGaAs transistors (with the gate length L = 250 nm) with two-dimensional electron gas in the channel has been studied at T = 4.2 K. For these transistors, it is shown for the first time that the maximum of the response (the drain-source photovoltage) shifts with an increasing frequency to the region of higher gate voltages in accordance with the Dyakonov-Shur theory. It is shown that, as temperature is increased to 77 K, the dependence of the photovoltage on the gate voltage becomes nonresonant, which is caused by a decrease in the mobility.