Frequency dependent capacitance and conductance properties of Schottky diode based on rubrene organic semiconductor

Abstract

Al/rubrene/p-Si Schottky diode has been fabricated by forming a rubrene layer on p type Si by using the spin coating method. The frequency dependent capacitance–voltage (C–V–f) and conductance–voltage (G–V–f) characteristics of Al/rubrene/p-Si Schottky diyotes has been investigated in the frequency range of 5kHz–500kHz at room temperature. The C–V plots show a peak for each frequency. The capacitance of the device decreased with increasing frequency. The decrease in capacitance results from the presence of interface states. The plots of series resistance–voltage (Rs−V) gave a peak in the depletion region at all frequencies. The density of interface states (Nss) and relaxation time (τ) distribution profiles as a function of applied voltage bias have been determined from the C–V and G–V measurements. The values of the Nss and τ have been calculated in the ranges of 8.37×1011–4.85×1011eV−1cm−2 and 5.17×10−6–1.02×10−5s, respectively.