- Structural defects, found in gallium-phosphide nanowires, grown from Au catalyst on InP 〈 111 〉 B substrate using metal organic molecular beam epitaxy, were extensively studied using Transmission Electron Microscopy (TEM). Several types of growth were analyzed: pure axial, axial–lateral and self catalyzed. Pure axially grown nanowires were found to be single crystals with wurzite crystal structure and Ga-polarity. These nanowires contained threading edge dislocation along the wire axis. The axial–lateral nanowires grew with zinc blend crystal structure and exhibited polycrystalline nature. Self catalyzed single crystalline nanowires possessed wurzite crystal structure with P-polarity and exhibited threading edge dislocations along their axis.