A Study of Transparent Conductive Aluminum-Doped Zinc Oxide Fabricated on a Flexible Polyethersulphone(PES) Substrate

Aluminum-doped zinc oxide (AZO) thin films, a, most promising transparent conducting oxide (TCO) material, were deposited on flexible and transparent polyethersulphone (PES) substrates by using an RF magnetron sputtering method. The films were well grown predominantly vertically to substrates with c-axis orientations, as on other rigid substrates. The substrate temperature during growth had no effect on the crystal orientation, but a higher temperature could enhance the electric and the optical properties. The resistivity, which decreases with increasing substrate temperature, showed a minimum electrical resistivity of similar to 2.07 x 10(-4) Omega.cm, and a high optical transmittance of over 90 % in the visible range without any thermal and plasma damage to the PES substrate. The results of the resistivity and of the transmittance in visible range showed that AZO/PES would be superior to ITO on PET, which has been widely studied up to now. These results reveal that AZO can be adopted as a TCO on a flexible polymer PES substrate for flexible OLED device application.