GaNAsSb/GaAs waveguide photodetector with response up to 1.6 μm grown by molecular beam epitaxy

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.