Optical reflectance studies of highly specular anisotropic nanoporous (111) InP membrane

摘要: High-precision optical angular reflectance measurements are reported for a specular anisotropic nanoporous (111) InP membrane prepared by doping-assisted wet-electrochemical etching. The surface morphology was investigated using scanning electron microscope imaging and revealed quasi-uniform self-organized network consisting of semiconductor 'islands' in the sub-wavelength regime. response studied at 405 nm (740 THz; UV), 633 (474 VIS) 1064 (282 NIR), exhibited retention basic macro-dielectric properties. Refractive index determinations demonstrate an anisotropy which is strongly dependent on wavelength incident light, exhibits interesting inversion (positive to negative) between nm. attributed reduced 'metallic' behaviour when subject above-bandgap illumination. For simplest case sub-bandgap irradiation, properties sample analysed terms effective refractive neff compared media approximations.