Gas source molecular beam epitaxy grown InGaAs(P)N-InP long-wavelength (/spl lambda/>1.65 μm) photodetectors using a solid arsenic source

We demonstrate InGaAs(P)N-InP-based long-wavelength (/spl lambda/>1.65 μm) p-i-n photodetectors grown lattice-matched to InP substrates using a solid As source. The background doping level in the absorption layer is significantly reduced from (5.0/spl plusmn/0.3)×10/sup 17/ cm/sup -3/ for gas source As grown devices to (3.5/spl plusmn/0.5)×10/sup 16/ cm/sup -3/ for solid source As grown devices with the same cutoff wavelength of 1.85 μm. The external quantum efficiency at a wavelength of 1.56 μm is 30% for the solid source grown detector as compared with 16% for the gas source grown detector due to the higher background doping and hence smaller depletion region width in the latter diode. Nitrogen-hydrogen complex formation and local strain-induced defects may significantly contribute to high free carrier concentrations observed in gas source As grown InGaAs(P)N layers.