Photothermal structural and optical changes in GaAs nanowires

Structural and optical changes in vertically arranged GaAs nanowires are examined using Raman spectroscopy. In this contribution, it is shown that the dissociation of arsenic from the GaAs lattice happens at temperatures which are reduced by about 220 K relative to bulk. The salient changes in the optical properties are easily seen in a microscopy and show for the first time that a laser can be used to tune the color of GaAs nanowires.