Abstract:

We describe a general synthesis of conductive gold thin films doped with entrapped organic molecules,and demonstrate, for the first time, the immobilization of a redox couple within an electrode in a singlestep. The resulting film is of dual properties: conductivity arising from the gold, and redox behaviororiginating from the entrapped molecule. Faster electron-transfer rates are found for the entrappedcase, compared to adsorption. The conductivity of the film affects the organic molecule–metal interactions,as seen in resistivity measurements, in Raman spectroscopy of the metal-entrapped molecules and froma remarkable red shift of 30 nm in emission spectroscopy. Doping is found to affect the work functionof gold. Thin conductive doped metal films are of relevance to a variety of applications such aselectrochemical detectors, electrode materials for electrochemical impedance spectroscopy, micro andnano electronics interconnects for packaging and for printed circuit boards. The ability to fine-tune thework function opens the possibility to design the desired energy level gaps for optoelectronic applicationssuch as light emitting diodes (LEDs), solar cells and transistors.