Material and ultrafast optoelectronic properties of furnace-annealed arsenic-ion-implanted GaAs

Abstract

Structural, electrical, and ultrafast optical properties of furnace-annealed arsenic-ion-implanted GaAs (GaAs:As+) has been investigated for its applications in ultrafast optoelectronics, From these studies, we determine that GaAs substrates implanted with 200-keV arsenic ions at 10(16) ions/cm(2) and furnace-annealed at 500 degrees C-600 degrees C would have recovered its crystallinity, be highly resistive, and exhibit picosecond photo-excited carrier lifetimes. The duration of the electrical pulses generated by photoconductive switches (PCS's) fabricated on the optimized material was approximate to 4 ps, The risetime (10%-90%) and 1/e falltime were, respectively, approximate to 2 and 3 ps, These results were measurement-system limited, We estimated the actual response to be approximate to 2 ps, consistent with a photo-excited carrier lifetime of approximate to 1.8 ps. The peak responsivity was greater than or equal to 4x10(-3) A/W. The dark current for the GaAs:As+ PCS biased at 40 V was as low as 5 nA. The break down field was higher than 150 kV/cm, These characteristics are comparable to those of state-of-the-art photoconductors such as LT-GaAs.