Abstract-Terahertz electroluminescence of shallow impurities in AlGaN/GaN heterostructures at 20 K and 110 K temperature

Ignas Grigelionis, Justinas Jorudas, Vytautas Jakštas, Vytautas Janonis, Irmantas Kašalynas, Pawel Prystawko, Piotr Kruszewski, Michal Leszczyński,



https://www.sciencedirect.com/science/article/pii/S1369800118319425


Terahertz (THz) electroluminescence of shallow impurities in the AlGaN/GaN HEMT structures grown either on sapphire or silicon carbide substrates were studied in this work. The radiative electron transitions $2p-1s$ in the oxygen and silicon donors as well as additional $c-1s$ transitions in the carbon atoms also were identified by THz emission spectroscopy at the temperatures of 110 K and 20 K, respectively. Moreover, the thermal quenching effect of the THz electroluminescence signals was found to occur at much higher electrical powers that were injected in the HEMT structures grown on silicon carbide as compared to that grown on the sapphire substrate.

Abstract-Electrically controlled wire-channel GaN/AlGaN transistor for terahertz plasma applications

Greg Cywinski, Piotr Kruszewski, I. Yahniuk, S. L. Rumyantsev

https://www.researchgate.net/publication/324049558_Electrically_controlled_wire-channel_GaNAlGaN_transistor_for_terahertz_plasma_applications

We report on a design of fin-shaped channel GaN/AlGaN field-effect transistors developed for studying resonant terahertz plasma oscillations. Unlike common two dimensional FinFET transistor design, the gates were deposited only to the sides of the two dimensional electron gas channel, i.e., metal layers were not deposited on the top of the AlGaN. This side gate configuration allowed us to electrically control the conductivity of the channel by changing its width while keeping the carrier density and mobility virtually unchanged. Computer simulations and analytical model describe well the general shape of the characteristics. The side gate control of the channel width of these transistors allowed us to eliminate the so-called oblique plasma wave modes and paves the way towards future terahertz detectors and emitters using high quality factor plasma wave resonances.