Effect of mesh patterning with UV pulsed-laser on optical and electrical properties of ZnO/Ag–Ti thin films

In this study, the ZnO/Ag–Ti structure for transparence conducting oxide (TCO) is investigated by optimizing the thickness of the Ag–Ti alloy and ZnO layers. The Ag–Ti thin film is deposited by DC magnetron sputtering and its thicknesses is well controlled. The ZnO thin film is prepared by sol–gel method using zinc acetate as cation source, 2-methoxiethanol as solvent and monoethanolamine as solution stabilizer. The ZnO film deposition is performed by spin-coating technique and dried at 150 °C on Corning 1737 glass. Due to the conductivity of ZnO/Ag–Ti is dominated by Ag–Ti, the sheet resistance of ZnO/Ag–Ti decrease dramatically as the thickness of Ag–Ti layer increases. However, the transmittances of ZnO/Ag–Ti become unacceptable for TCO application after the thickness of Ag–Ti layer beyond 6 nm. The as-deposited ZnO/Ag–Ti structure has the optical transmittance of 83% @ 500 nm and the low resistivity of 1.2 × 10−5 Ω-cm. Furthermore, for improving the optical and electrical properties of ZnO/Ag–Ti, the thermal treatment using laser is adopted. Experimental results indicate that the transmittance of ZnO/Ag–Ti is improved from 83% to 89% @ 500 nm with resistivity of 1.02 × 10−5 Ω-cm after laser drilling. The optical spectrum, the resistance, and the morphology of the ZnO/Ag–Ti will be reported in the study.