Ge incorporation in gallium oxide nanostructures grown by thermal treatment

Effective doping of semiconductor oxide nanostructures is needed to control n-type conductivity; however, out-diffusion of impurities in high quality crystals is still a bottleneck in nanotechnology. Here, germanium-doped gallium oxide (beta-Ga2O3) nanowires have been grown by a thermal evaporation method. Two temperatures, close to Ge melting point, were chosen for the dynamic annealing of metallic gallium and germanium powders. At 840 degrees C, Ga(2)O(3)nanowires and nanobelts grow along theborcdirection, leaving gallium germanate particles at the tip in both cases. Wider structures were produced at 940 degrees C, decorated with a Ge nanocrystal at the end. Transmission electron microscopy has been used to establish the vapor-liquid-solid-like growth process for the formation of these structures. The influence of Ge incorporation in the nanostructures has been assessed by cathodoluminescence and micro-Raman spectroscopy. The presence of Ge in beta-Ga(2)O(3)nanostructures is essential for electronic and optoelectronic applications since Ge is potentially the most effective n-type dopant for beta-Ga2O3.