Strongly photonic macroporous gallium phosphide networks

A photo-assisted electrochemical etching technique to fabricate macropores in single-crystalline gallium phosphide (GaP) with variable porosity has be en developed. Scanning electron microscopy and x-ray diffraction experiment s confirm that the material consists of three-dimensional, interconnected r andom networks with pore sizes of about 150 nanometers. Optical transmissio n measurements demonstrate that the nonabsorbing disordered structures stro ngly scatter Light. The photonic strength is controlled by filling the pore s with liquids of different refractive indices, Macroporous gallium phosphi de filled with air has the highest scattering efficiency for Visible light.