Fabrication of ITO particles using a combination of a homogeneous precipitation method and a seeding technique and their electrical conductivity

• This paper proposes a method to produce indium tin oxide (ITO) particles.
• Precursor particles were produced using a combination of a homogeneous precipitation method and a seeding technique.
• The ITO particles were fabricated by annealing the precursor particles.
• The ITO particles had an angular shape, a crystal structure of cubic ITO, and volume resistivity smaller than that of ITO fabricated using a co-precipitation method.
• Seeding of ITO nanocrystallites promoted the formation of a quasi-cubic structure and decreased the volume resistivity.

The present work proposes a method to fabricate indium tin oxide (ITO) particles using precursor particles synthesized with a combination of a homogeneous precipitation method and a seeding technique, and it also describes their electronic conductivity properties. Seed nanoparticles were produced using a co-precipitation method with aqueous solutions of indium (III) chloride, tin (IV) chloride aqueous solution and sodium hydroxide. Three types of ITO nanoparticles were fabricated. The first type was fabricated using the co-precipitation method (c-ITO). The second and third types were fabricated using a homogeneous precipitation method with the seed nanoparticles (s-ITO) and without seeds (n-ITO). The as-prepared precursor particles were annealed in air at 500 °C, and their crystal structures were cubic ITO. The c-ITO nanoparticles formed irregular-shaped agglomerates of nanoparticles. The n-ITO nanoparticles had a rectangular-parallelepiped or quasi-cubic structure. Most s-ITO nanoparticles had a quasi-cubic structure, and their size was larger than the n-ITO particles. The volume resistivities of the c-ITO, n-ITO and s-ITO powders decreased in that order because the regular-shaped particles were made to strongly contact with each other.