Investigation of structural, optical, electrical and mechanical properties of transparent conducting ‘Ag’ electrodes

The high flexibility and excellent optoelectrical properties of thin metal films hold great potential for their use as transparent conducting electrodes in large-area flexible optoelectronic devices. Thermally evaporated transparent conducting silver (Ag) thin films (48–75 nm) are characterized using X-ray diffraction, scanning electron microscopy, scanning probe microscopy, UV–Vis–NIR spectroscopy, Hall effect, Nanoindentation and Kelvin probe techniques. Significant textured growth along (111) crystal plane direction is observed. The film with least thickness exhibits interesting wrinkled surface morphology. Surface roughness is observed to increase with film thickness. High transmittance and considerable transparency are observed in UV and NIR regions, respectively. Surface work function (4.7–4.9 eV) is determined from Kelvin probe measurements. Nanoindentation studies indicate reduced hardness with increasing film thickness. These experiments suggest that Ag film of thickness 63 nm shows better optical and electrical properties and may be a potential transparent conducting supplement for specific applications like transparent electrodes and interconnects.