Modified reflection in birefringent layers of core-shell semiconductor nanowires

Birefringent layers of GaP nanowires are grown by metal-organic vapor phase epitaxy on top of a GaP substrate. We modified the reflection of the as-grown layer by adding a shell of 12 nm of SiO₂ around the nanowires. The effect of the shell on the effective refractive indices of the birefringent nanowire layer was calculated using Maxwell-Garnett effective medium theory for coated cylinders. The large change of the reflection due to the shell renders nanowire layers a promising material for sensing applications.