Emission of terahertz (THz) radiations from interdigitated GaN quantum-wells structures under DC-bias has
been measured at room temperature. This measurements has been performed by a 4K Si-Bolometer associated
with a Fourier Transform Spectrometer. Using an analytical model, we have shown that the observed peak
at approximately 3 THz due to 2D ungated plasma-waves oscillations in the quantum well, is emitted by the
metallic contacts of our device acting as antennas.
We report on measurements of radiation transmission in the 0.220-0.325 THz and 0.75-1.1 THz
frequency ranges through GaN quantum wells grown on sapphire substrates at nitrogen and room
temperatures. Significant enhancement of the transmitted beam intensity with applied voltage is
found at nitrogen temperature. This effect is explained by changes in the mobility of two-dimensional
electrons under electric bias. We have clarified which physical mechanism modifies the electron mobility
and we suggest that the effect of voltage-controlled sub-terahertz transmission can be used for
the development of electro-optic modulators operating in the sub-THz frequency range.