Cathodoluminescence spectrum-imaging of a gallium arsenide (GaAs) nanowire
Data courtesy of Dr. U. Jahn, Paul-Drude-Institut für Festkörperelektronik.
(a) Secondary electron image of a 200 nm diameter GaAs nanowire; (b) Cathodoluminescence spectrum-image displaying energy plane 1.46 ± 0.02 eV; (c) Individual cathodoluminescence spectrum extracted from spectrum-image with single peak at 1.45 eV; (d) Map of central energy of luminescence; change in wavelength is associated with a transition from zincblende (1.425 eV) to wurtzite crystal structure; wurtzite phase is calculated to have 55 meV larger band gap than zincblende phase; (e) Map of FWHM along nanowire.