A polymer Schottky diode carrying a chimney for selective doping

A device structure of polymer Schottky diodes enabling selective doping of polymer has been proposed. The device has a Ni grid anode with a chimney as a reservoir of dopant solution at the back of the cathode. The forward-bias current of the device was enhanced two orders of magnitude upon doping by nitromethane solution of FeCl3 for 10 min, while the reverse-bias current remained unchanged, indicating considerable reduction of series resistance of the device upon selective doping. It has also been found that the penetration depth of dopant depends significantly on the solvent, i.e. nitromethane eventually gives complete doping of a 50 mum thick PAT6 film, to induce cathode corrosion, while acetonitrile gives only shallow penetration. The device structure and doping procedure proposed may also be useful in reducing the series resistance of polymer photovoltaic devices.