Synthetic analysis on the IZTO thin films deposited on various plastic substrates with the buffer layer

Buffer layers, such as SiO 2 , may prevent impurities from permeating into the depositing film. Thus, the effects of buffer layer thickness on indium-zinc-tin oxide (IZTO) thin films were investigated. IZTO thin films are applied to transparent conductive oxide, and SiO 2 is used as a material for the buffer layer. Before depositing the IZTO by RF magnetron sputtering, the SiO 2 buffer layers were deposited on different plastic substrates, such as polyether sulfone, polyethylene terephthalate, and polyethylene naphthalate (PEN), by plasma enhanced chemical vapor deposition. The resulting structural, morphological, electrical, and optical properties were measured and analyzed. By using the obtained values of the electrical and optical properties, the figure of merit for transparent devices designed by Haacke was calculated. As a result, we conclude that the IZTO thin film deposited on a PEN substrate with a 30 nm thick SiO 2 buffer layer has the finest properties, which are a resistivity of 2.13 × 10 −3 Ω-cm, sheet resistance of 8.875 Ω sq −1 , Hall mobility of 5.99 cm 2 V −1 s −1 , carrier concentration of 3.671 × 10 21 cm −3 , and transmittance of 80.26% at 550 nm. In addition, the figure of merit calculated for this sample was 12.50 × 10 −3 /Ω. These results indicate that the proposed structure is suitable for flexible display devices and flexible solar cells.