We present a detailed study of the photoconductive antennas made from heavy-ion-irradiated In 0.53Ga 0.47As material. The optical and transport properties of ion-irradiated In 0.53Ga 0.47As material are characterized. The terahertz waveforms emitted and detected by ion-irradiated In 0.53Ga 0.47As photoconductive antennas excited by 1.55 μm wavelength femtosecond laser pulses are reported and the effect of the carrier lifetime on the terahertz signal characteristics emitted by such devices is analysed. The performances of ion-irradiated In 0.53Ga 0.47As photoconductive antennas excited by 1.55 μm and also by 0.8 μm wavelength femtosecond laser pulses are compared to those of similar low-temperature-grown GaAs photoconductive antennas. To cite this article: J. Mangeney, P. Crozat, C. R. Physique 9 (2008).