Indium Tin Oxide (ITO) Coatings Fabricated using Nanoparticle Slurry and Sol

Indium tin oxide (ITO) coatings were made using an ITO slurry and an ITO sol. This was achieved by dispersing nanosized ITO powder in a mixed solvent without any dispersant and developing an adhesive ITO sol from indium acetate and tin tetrachloride in a mixture of DMF and n-butanol. Coating was carried out in one step by spin coating an ITO slurry, which was then followed by an ITO sol over it. Here, the sol penetrates into the nano ITO particle layers to make them adhere to each other as well as to a glass substrate. This is then followed by sintering at 500$^{\circ}C$ for 1 h to produce a uniform film consisting of ITO particles of about 50 nm and 10 nm. ITO films were obtained with sheet resistances from 450 to 1500 ohm/${\Box}$ by varying spin speed and concentration. Transmittance is higher than 90% at 550 nm.