VLS growth of ITO whiskers prepared by the electron shower method

Indium tin oxide (ITO) whiskers were gown by VLS (vapour-liquid-solid) mechanism, using the electron shower method. The whiskers were grown above 200 degrees C, and the deposition rate was above 0.6 nm/s. The electron shower controlled the size of the whiskers, and the size was 30 nm in diameter and 600 nm in length. The whiskers grew along the substrate at t < 300 s, but grew in a direction perpendicular to the substrate at t > 300 s. When the ITO whiskers grown along the substrate were used as NO2 gas sensor, the sensitivity was 340, and about 300 times higher than those of the whiskers grown in a direction perpendicular to tile substrate and plate-like ITO crystallites.