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 similar to 20 V in the hole- only device configuration. The characteristics are studied in the temperature range 310-210 K. In the intermediate voltage range the J-V characteristics follow J proportional to Vl+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.