Nonstoichiometric GaAs for terahertz optoelectronic applications

Low-temperature MBE grown (LTG) GaAs layers and ion-implanted GaAs were investigated from the viewpoint of their application in optoelectronic devices for the terahertz (THz) frequency range. Material parameters most relevant for such applications (electron and hole trapping times and mobilities) were characterized by employing femtosecond optical pulses for the photoexcitation and mid-infrared or THz radiation pulses for probing nonequilibrium carrier distributions. The dependences of these parameters on the growth and anneal conditions were determined and discussed.