InGaAsP/InP photodiodes antireflectively coated with InP native oxide

Usefulness of the anodically grown native oxide film in InP surface is demonstrated as an antireflection coating of InGaAsP/InP DH photodiodes. The reflection of the InP is 30 percent, while that with coating is 2.8 percent in the wavelength region considered. The quantum efficiencies of 64 percent for the uncoated diode and 82 percent for the coated one were obtained. Some important optical properties of the anodically oxidized film are also measured.