Abstract:A new method was presented to improve organic diode current-voltage (I-V) characteristics by using doped p-type material. The organic diodes with one-layer poly (3-alkylthiophene) (PAn=8T) and PAn=8T doped with various amounts of poly (N-vinylcarbazole) (PVK) (Pan=8T/PVK) sandwiched between an indium/tin oxide (ITO) and an aluminium cathode were fabricated by spin coating onto ITO respectively. It was found that the I-V characterisitcs were improved by doping with PVK in PAn=8T diode, and it was known that the exponent of the fitting equation has a maximum value by the best fit power curve if the doped PVK amount is moderate.