Effect of electron irradiation on the THz emission of low temperature-grown GaAs/Si epilayers
We examine the effect of electron irradiation on the terahertz (THz) emission of low temperature-grown gallium arsenide on silicon (LT-GaAs/Si) epilayers. The GaAs layers were prepared on Si (100) and (111) substrates at 400°C via molecular beam epitaxy (MBE) and were irradiated with 2.5 MeV electrons to an absorbed dose of 200 kGy. By comparing the non-irradiated and 200-kGy-irradiated epilayers, we found that electron irradiation affects the crystallinity of the MBE-grown epilayers. On the other hand, THz time domain spectroscopy (THz-TDS) measurements reveal that there is no significant difference in the THz emission characteristics between the non-irradiated and electron-irradiated LT-GaAs/Si epilayers. These results suggest that MBE-grown LT-GaAs/Si epilayers are robust to electron irradiation and can be developed further for radiation-durable applications.