Properties of Transparent Conductive Zinc Oxide Films Deposited on COP Substrates by PLD Method

Abstract

The Al-doped ZnO (AZO) films and ZnO buffer layer were deposited on cyclo-olefin polymer (COP) substrates by pulsed laser deposition (PLD) method using ArF excimer laser (λ = 193 nm) with an energy densities of 1.0 ∼ 2.5 J/cm2. Film structure was composed of a 150 nm-thick AZO film, a 100 nm-thick ZnO buffer layer, and a 188 μm-thick COP substrate. As a result, in the range of 1.0 ∼ 2.5 J/cm2, Hall mobility and carrier concentration were found to decrease linerly. Therefore, the lowest resistivity of 2.77×10-4 Ω-cm was obtained at laser energy density of 1.0 J/cm2. By the results of FE-SEM photograph and AFM image of a AZO / ZnO / COP structure deposited at a laser energy density of 1.0 J/cm2, it was found that smooth-surface-films with average roughness of 4.26 nm and AZO / ZnO films of good quality without cracked or flaked conditions were obtained. This will enables us to realize low-cost, lightweight, and flexible devices.