Properties of Au nanolayers on polyethyleneterephthalate and polytetrafluoroethylene

Gold nanolayers deposited by sputtering on polytetrafluoroethylene (PTFE) and polyethyleneterephthalate (PET) films were studied in this work. The influence of sputtering time on the layer thickness, surface morphology and roughness was determined by various methods (i.e. atomic absorption spectroscopy, focused ion beam and scanning electron microscopy). Sheet resistance and concentration and mobility of free charge carriers in Au nanolayers were determined using the Van der Pauw method. Surface morphology was determined using atomic force microscopy (AFM). After gold deposition on PET, the surface roughness increases and the surface morphology changes in contrast with PTFE coated under the same conditions. With the increasing sputtering time, the layer resistance decreases rapidly for both polymer substrates. Electrically continuous coverage is achieved for the gold layer with an average thickness of ca 4 nm for PET and ca 5 nm for PTFE. Continuous layers on both polymers exhibit the same concentration of free charge carriers. Lower mobility of the charge carriers was found on rougher Au/PTFE.