Microstructural and electrical properties of Ga2O3 nanowires grown at various temperatures by vapor-liquid-solid technique

Gallium oxide (Ga2O3) nanowires were grown at various temperatures by vapor-liquid-solid method on Au-nanodots prepared at 500 degrees C on SiO2/Si substrates. The average size of Au-nanodots was approximately 20 nm. The optimum conditions for the growth of nanowires were in the temperature range of 700-900 degrees C. The diameter and the length of nanowires grown from 700 to 900 degrees C are 10-40 min and several micrometers, respectively. The samples grown at 950 degrees C exhibit the various shapes of nanobelts and nanosheets including nanowires. On the other hand, Ga2O3 nanowires were not formed at 1000 degrees C. The nanowires grown at 900 degrees C were beta-Ga2O3 with a crystal structure of single crystal. For applications of H-2 gas sensor, the response values of Ga2O3 nanowires grown at 900 degrees C are quite high and the response time is in the range of 48-52 s. However, gas sensing properties should be more analyzed. (C) 2009 Elsevier B.V. All rights reserved.