The Sn/pyronine-B/p-Si Schottky structures have been obtained by sublimation of the organic compound pyronine-B onto the top of a p-Si surface. Barrier height and ideality factor value of 0.79 eV and 1.13, respectively, for the device have been determined from the forward-bias current-voltage (I-V characteristics. The interface state density obtained from the forward bias high and low capacitance-voltage characteristics increases exponentially with bias between the midgap and the top of the valance band, from 2.15 x 10(11) cm(-2) eV(-1) at (0.79-E-v) eV to 1.16 x 10(12) cm(-1) eV(-1) at (0.53-E-v) eV. These values have been compared to those of the metal/Si structures in the literature, and it is seen that the presence of the nonreactive organic materials at the inorganic semiconductor and metal interface may obstruct the generation of the interface states at the semiconductor surface that strongly influence the Schottky barrier formation. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.