Electrically driven terahertz radiation of 2DEG plasmons in AlGaN/GaN structures at 110 K temperature

We experimentally observed a terahertz (THz) radiation of electrically driven 2D electron gas (2DEG) plasmons in AlGaN/AlN/GaN structures at T = 110 K. The grating with a period of 1.0 μm and a filling factor of 0.35 was used to couple electromagnetic radiation out from the plasmonic sample excited in a pulsed regime. The peak power radiated from ungated 2DEG plasmons at a frequency of 5.0 THz under an electric field of 450 V/cm was up to 940 nW. The intensity of the radiation was sufficient to measure spectra with a conventional far-infrared Fourier transform spectrometer. The analysis of the data revealed that the 2DEG plasmon radiation was superimposed with the black-body radiation of the sample and electroluminescence of the impurities. The strategy to reach higher powers of THz emission for practical applications is discussed.