Optoelectric Property and Flexibility of Tin-Doped Indium Oxide (ITO) Thin Film

Transparent conducting electrodes (TCEs) are key materials for electronic devices such as flat panel displays (e.g., a liquid crystal display and a light emitting diode display), photovoltaic cells, and transparent transistors. Tin-doped indium oxide (ITO) is known to be highly conductive/transparent, but rigid. In this study, very thin (<35 nm) ITO films with amorphous phases were prepared on flexible substrates and their optoelectric properties investigated. A 10 nm-thick ITO film was also fabricated. Because of their low thickness, their transmittances were above 80% at ˜550 nm wavelength. Their sheet resistances were below 0.7 kΩ/sq and decreased with increasing film thickness. An interesting observation was that their sheet resistances were nearly unchanged even at a bending radius of ˜2 mm. These optoelectric properties and flexibility demonstrate that the ITO films fabricated in this study are suitable transparent conducting oxides for the electrodes of flexible optoelectric devices.