Conductive molecularly doped gold films

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 single step. The resulting film is of dual properties: conductivity arising from the gold, and redox behavior originating from the entrapped molecule. Faster electron-transfer rates are found for the entrapped case, 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 from a remarkable red shift of 30 nm in emission spectroscopy. Doping is found to affect the work function of gold. Thin conductive doped metal films are of relevance to a variety of applications such as electrochemical detectors, electrode materials for electrochemical impedance spectroscopy, micro and nano electronics interconnects for packaging and for printed circuit boards. The ability to fine-tune the work function opens the possibility to design the desired energy level gaps for optoelectronic applications such as light emitting diodes (LEDs), solar cells and transistors.