Dependence of Meyer–Neldel energy on energetic disorder in organic field effect transistors

Meyer–Neldel rule for charge carrier mobility was studied in C60-based organic field effect transistors (OFETs) fabricated at different growth conditions which changed the degree of disorder in the films. The energetic disorder in the films was found to correlate with a shift in the Meyer–Neldel energy, which is in excellent agreement with the predictions of a hopping-transport model for the temperature dependent OFET mobility in organic semiconductors with a Gaussian density-of-states (DOS). Using this model the width of the DOS was evaluated and it was found to decrease from 88 meV for the films grown at room temperature to 54 meV for films grown at 250 °C.