Coherent diffraction imaging of a single epitaxial InAs nanowire using a focused x-ray beam

The cross section of an InAs nanowire with a diameter of 150 nm epitaxially grown on a 111-oriented InP substrate was characterized using a combination of x-ray scanning microdiffraction and coherent diffraction imaging. Using an x-ray beam focused by a Fresnel zone plate, we were able to scan in real space and hence localize single nanowires on the substrate in the as-grown epitaxial state. For one single nanowire, the three-dimensional coherent intensity distribution in reciprocal space was mapped around the (111) InAs reflection. Using phase retrieval algorithms, the cross section of the wire was reconstructed with a spatial resolution of 8 nm along one direction.