We report a photoconductive switch with GaNAsSb as active material for microwave switching application. The GaNAsSb layer was grown by molecular beam epitaxy in conjunction with a rf plasma-assisted nitrogen source and a valved antimony cracker source. The 0.5 μm thick GaNAsSb photoabsorption layer contains 3.5% of N and 9% of Sb. The switch exhibits pulsed response with full width at half maximum of 30 ps and photoresponse of up to 1.6 μm. In microwave switching application, the switch shows ON/OFF ratio of 11 dB at 1 GHz and response up to 15 GHz.

GaNAsSb/GaAs p-i-n photo notdetectors with an intrinsic GaNAsSb photoabsorption layer grown at 350 degrees C, 400 degrees C, 440 degrees C and 480 degrees C, have been prepared using radio-frequency nitrogen plasma-assisted molecular beam epitaxy in conjunction with a valved antimony cracker source. The i-GaNAsSb photoabsorption layer contains 3.3% of nitrogen and 8% of antimony, resulting in DC photo-response up to wavelengths of 1350 nm. The device with i-GaNAsSb layer grown at 350 degrees C exhibits extremely high photoresponsivity of 12A/W at 1.3 microm. These photodetectors show characteristics which strongly suggest the presence of carrier avalanche process at reverse bias less than 5V.

International audienceWe report a photoconductive switch using low temperature grown GaNAsSb as the active material. The GaNAsSb layer was grown at 200 °C by molecular beam epitaxy in conjunction with a radio frequency plasma-assisted nitrogen source and a valved antimony cracker source. The low temperature growth of the GaNAsSb layer increased the dark resistivity of the switch and shortened the carrier lifetime. The switch exhibited a dark resistivity of 107 Ω cm, a photo-absorption of up to 2.1 μm, and a carrier lifetime of ∼1.3 ps. These results strongly support the suitability of low temperature grown GaNAsSb in the photoconductive switch application

We present the dc performance of a high-quantumefficiency GaNAsSb/GaAs p-i-n waveguide photodetector. GaNAsSb with N and Sb contents of 3.3% and 8%, respectively, is sandwiched by AlGaAs/GaAs cladding layers. Two types of device epilayer structures, i.e., with and without AlGaAs cladding layer, show high responsivity values of 0.72 and 0.55 A/W, respectively, at a reverse bias voltage of 10 V and a wavelength of 1.3 μm. These correspond to internal quantum efficiencies of 96.7% and 73.9%, respectively. A linear increase in photocurrent with an increase in optical power up to 8 mW and also a high reverse breakdown voltage of −16.6 V were obtained.Index Terms-Dilute nitride, GaNAsSb, responsivity, waveguide photodetector (WGPD).

We present a GaNAsSb/GaAs p-i-n waveguide photodetector operating in the 1.0–1.6 μm wavelength range with enhanced photoresponsivity compared to a top-illuminated photodetector fabricated using the same material system. The device consists of a strained GaNAsSb layer, with N and Sb contents of 3.5% and 18%, respectively, sandwiched between GaAs:Si (n-type) and GaAs:C (p-type) layers. X-ray reciprocal space map of the GaNAsSb layer before device fabrication showed that the film relaxation is ∼1%. At 1.55 μm, photoresponsivities of 0.25 and 0.29 A/W for devices with 6.5 and 10 μm ridge width, respectively, was demonstrated.