Effect of non-zero Schottky barrier on the J-V characteristics of organic diodes.

Current-voltage (J-V) characteristics of poly(3-hexylthiophene) (P3HT) are studied at different temperatures upto high voltages approximately 20V in the hole-only device configuration. The characteristics are studied in the temperature range 310-210K. In the intermediate voltage range the J-V characteristics follow J proportional to V(l+1), where l > 1. As the voltage increases to high values J still varies as a power law i.e. as V(m), but contrary to the literature result m becomes < 2. This behavior is explained theoretically in terms of non-zero injection Schottky barriers. The complete analytical expressions for the actual trap filled limit voltage (V'(TFL)) and J-V curves beyond V'(TFL) are presented.