High photocarrier mobility in ultrafast ion-irradiated In_{0.53}Ga_{0.47}As for terahertz applications
Résumé
Optical pump–terahertz (THz) probe spectroscopy was used for investigation of electron dynamics in In_{0.53}Ga_{0.47}As films irradiated by heavy ions (Br^+) at doses from 10^9 to 10^{12} 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 cm^2 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 In_{0.53}Ga_{0.47}As shows promising properties for the development of THz systems using telecommunication based technology