Terahertz radiation from heavy-ion irradiated In/sub 0.35/Ga/sub 0.47/As photoconductive antenna at 1.55 /spl mu/m

We measured the terahertz (THz) emission from heavy-ion irradiated In/sub 0.35/Ga/sub 0.47/As photoconductive (PC) antennas excited at 1550 nm. The In/sub 0.35/Ga/sub 0.47/As layer irradiated at 10/sup 12/ cm/sup -2/ shows a carrier lifetime shorter than 200 fs, a steady-state mobility of 490 cm/sup 2/V/sup -1/s/sup -1/, and a dark resistivity of 3.1 /spl Omega/cm. The spectrum of the electric field radiated from the heavy-ion irradiated In/sub 0.35/Ga/sub 0.47/As antenna extends beyond 2 THz. Comparative measurements performed on In/sub 0.35/Ga/sub 0.47/As PC antennas irradiated at 10/sup 11/ cm/sup -2/ and 10/sup 12/ cm/sup -2/ demonstrate the impact of the defect center scattering on the photo-excited carrier mobility.