Particle-assisted Gax In1− x P nanowire growth for designed bandgap structures

Non-tapered vertically straight GaxIn1− xP nanowires were grown in a compositional range from Ga 0.2 In 0.8 P to pure GaP in particle-assisted mode by controlling the trimethylindium, trimethylgallium and hydrogen chloride flows in metal–organic vapor phase epitaxy. X-ray energy dispersive spectroscopy in transmission electron microscopy revealed homogeneous radial material composition in single nanowires, whereas variations in the material composition were found along the nanowires. High-resolution x-ray diffraction indicates a variation of the material composition on the order of about 19% measuring an entire sample area, i.e., including edge effects during growth. The non-capped nanowires emit room temperature photoluminescence strongly in the energy range of 1.43–2.16 eV, correlated with the bandgap expected from the material composition.