Sintering of tin-doped indium oxide (Indium-Tin-Oxide, ITO) with Bi2O3 additive

Tin-doped indium oxide (Indium-Tin-Oxide, ITO) is known as a poorly sintera ble material. Densification of ITO powders with relatively large particle s ize (1-2 mu m) was enhanced remarkably by the additive (Bi2O3) whose meltin g point is lower than the sintering temperature. The maximum bulk density o f 6.75 g/cm(3) (relative density; 95%) was obtained when pressurelessly sin tered in air at 1500 degrees C for 5 hours using the starting material cont aining 2.0 mass % Bi2O3, while the density was approximately equal to the g reen density when sintered using the starting material without Bi2O3. Incre ase of electrical resistivity caused by the additive was suppressed success fully when a small amount of Bi2O3 (1.0 mass %) was added and heated at 150 0 degrees C. The bismuth was eliminated from the sintered body to achieve t he low resistivity (8.1 x 10(-4) ohm cm) which was approximately equal to t hat of the pure ITO. (C) 1998 Kluwer Academic Publishers.