Electrical and thermal properties of photoconductive antennas based on In$_{x}$Ga$_{1-x}$As ($x>$ 0.3) with a metamorphic buffer layer for the generation of terahertz radiation

The results of studies of the electrical and thermal properties of photoconductive antennas for terahertz-radiation generation are reported; these antennas are fabricated on the basis of low-temperaturegrown GaAs (LT-GaAs) and In$_{x}$Ga$_{1-x}$As with an increased content of indium ($x>$ 0.3). It is shown that the power of Joule heating PH due to the effect of “dark” current in In$_{x}$Ga$_{1-x}$As exceeds the same quantity in LT-GaAs by three–five times. This is due to the high intrinsic conductivity of In$_{x}$Ga$_{1-x}$As at $x>$ 0.38. Heatremoval equipment for the photoconductive antenna has been developed and fabricated. The results of numerical simulation show that the use of a heat sink makes it possible to reduce the operating temperature of the antenna based on LT-GaAs by 16%, of the antenna based on In$_{0.38}$Ga$_{0.62}$As by 40%, and for antennas based on In$_{0.53}$Ga$_{0.47}$As by 64%.