The Conductance- and Capacitance-Frequency Characteristics of the Rectifying Junctions Formed by Sublimation of Organic Pyronine-B on p-Type Silicon

Abstract

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±0.06 eV for this structure have been obtained from the forward bias current–voltage ( I– V) 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 4.93×10 10 cm −2 eV −1 in (0.79− E v) eV to 3.67×10 13 cm −2 eV −1 in (0.53− E v) eV. Furthermore, the relaxation ranges from 3.80×10 −3 s in (0.53− E v) eV to 4.21×10 −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.