The investigation of ZnS/Au/ZnS transparent conductive films with different Au layer thickness

ZnS/Au/ZnS (ZAZ) transparent conductive tri-layer films with different Au layer thickness have been prepared by a pulsed laser deposition technique, and the effect of Au layer thickness on the optical and electrical properties of ZAZ films has been studied in detail. As-deposited ZAZ films showed an intense X-ray diffraction peak corresponding to ZnS (111) orientation and a very weak peak belonging to the Au (111) plane. The optical transmittance first increases and then decreases with the increase of Au layer thickness, which is due to the fact that Au changes from discontinuous island-shape to near-continuous structure when Au increases from 2 to 10 nm, and when Au is above 10 nm, the reflection of Au layer is enhanced. With the increase of Au layer thickness, both the sheet resistance and the resistivity of ZAZ films decrease, and the carrier concentration and the mobility increase. When the Au layer thickness is 10 nm, ZAZ films have the best figure of merit of 2.44 × 10−3 Ω−1.