Abstract
LT-GaAs, with subpicosecond photoexcited carrier lifetime, is currently the premier material for fabricating ultrafast optoelectronic devices. An alternate arsenic-rich material, arsenic-ion-implanted (As + - implanted) GaAs, or GaAs:As + has recently emerged. The structural and electrical characteristics of GaAs:As + and LT-GaAs are very similar. Photoexcited carrier lifetime as short as 300 fs in GaAs:As + implanted at dose and energy of 10 12 ions/cm 2 and 200 KeV 3 . The effect of the thermal annealing process on the lifetime of photoexcited carriers in GaAs:As + is examined in this paper.