Terahertz photomixing in high energy oxygen- and nitrogen-ion-implanted GaAs

In this letter, the authors elaborate a detailed study of ion-implanted GaAs terahertz photomixers. The authors implanted several GaAs samples with oxygen and nitrogen ions with energies between 2 and 3MeV and doses ranging from 2×1011to3×1013cm−2. The samples were processed by patterning metal-semiconductor-metal structures on the feed point of self-complementary log-periodic spiral broadband antennas. From dc measurements and analysis of frequency roll-off in the 100GHz–1THz range under variable bias conditions, the authors studied systematically the carrier trapping time, terahertz power, and photocurrent dependence on applied voltage and frequency for the different samples.