The conductance and capacitance-frequency characteristics of the organic compound (pyronine-B)/p-Si structures

The nonpolymeric organic compound pyronine-B thin film on a p-type Si substrate has been formed by the process of adding a solution of pyronine-B in methanol and evaporating the solvent. It has been seen that the pyronine-B/p-Si contact shows the rectifying behavior. The barrier height and ideality factor values of 0.65 eV and 1.50, respectively, for this structure have been obtained from the forward bias current-voltage (1-V) characteristics. The energy distribution of the interface states and their relaxation time by means of the conductance method and Schottky capacitance spectroscopy (SCS) method have been determined in the energy range from (0.41 - E-V) to (0.65 - E-V) eV. It has been seen that the interface state density has an exponential rise with bias from the mid-gap towards the top of the valance band. The relaxation time shows a slow exponential rise with bias from the top of the valance band towards the mid-gap. It has been seen that the conductance method in the determination of the energy distribution of the interface states is more appropriate than the SCS method. (C) 2003 Elsevier Science B.V. All rights reserved.