The rectifying junction characteristics of the organic compound pyronine-B film on a p-type Si substrate has been studied. The pyronine-B has been sublimed on the top of p-Si surface. The barrier height and ideality factor values of 0.79 +/- 0.04 and 1.13 +/- 0.06eV for this structure have been obtained from the forward bias current-voltage (I-P) characteristics. From the low capacitance-frequency (C-f) characteristics as well as conductance-frequency (G-f) characteristics, the energy distribution of the interface states and their relaxation time have been determined in the energy range of (0.53-E-v)-(0.79-E-v)eV taking into account the forward bias I-V data. The interface state density N-ss ranges from 4.93 x 10(10) cm(-2) eV(-1) in (0.79-E-v) eV to 3.67 x 10(13) cm(-2) eV(-1) in (0.53-E-v)eV. Furthermore, the relaxation ranges from 3.80 x 10(-3)S in (0.53-E-v)eV to 4.21 x 10(-4) s in (0.79-E-v) eV. It has been seen that the interface state density has an exponential rise with bias from the midgap towards the top of the valence band. The relaxation time shows a slow exponential rise with bias from the top of the valence band towards the midgap. (C) 2002 Elsevier Science (USA).