High photocarrier mobility in ultrafast ion-irradiated In0.53Ga0.47As for terahertz applications

Optical pump-terahertz (THz) probe spectroscopy was used for investigation of electron dynamics in In0.53Ga0.47As films irradiated by heavy ions (Br+) at doses from 109 to 1012 cm-2. From the transient conductivity spectra, photoexcited electron lifetimes and mobilities were determined; their decrease is observed upon increase in the irradiation dose. At the highest dose, the material combines an electron lifetime of 0.46 ps with an exceptionally high photoexcited electron mobility of 3600 cm2 V-1 s-1. This last value is even higher than those reported for low-temperature-grown GaAs with similar electron lifetime. Due to its rather low band gap, heavy-ion irradiated In0.53Ga0.47As shows promising properties for the development of THz systems using telecommunication based technology.